\begin{thebibliography}{10}
\expandafter\ifx\csname url\endcsname\relax
  \def\url#1{\texttt{#1}}\fi
\expandafter\ifx\csname urlprefix\endcsname\relax\def\urlprefix{URL }\fi
\expandafter\ifx\csname href\endcsname\relax
  \def\href#1#2{#2} \def\path#1{#1}\fi

\bibitem{Chetyrkin:2009fv}
K.~G. Chetyrkin, et~al., {Charm and Bottom Quark Masses: an Update}, Phys. Rev.
  D80 (2009) 074010.
\newblock \href {http://arxiv.org/abs/0907.2110} {\path{arXiv:0907.2110}},
  \href {http://dx.doi.org/10.1103/PhysRevD.80.074010}
  {\path{doi:10.1103/PhysRevD.80.074010}}.

\bibitem{Novikov:1977dq}
V.~A. Novikov, et~al., {Charmonium and Gluons: Basic Experimental Facts and
  Theoretical Introduction}, Phys. Rept. 41 (1978) 1--133.
\newblock \href {http://dx.doi.org/10.1016/0370-1573(78)90120-5}
  {\path{doi:10.1016/0370-1573(78)90120-5}}.

\bibitem{Reinders:1984sr}
L.~J. Reinders, H.~Rubinstein, S.~Yazaki, {Hadron Properties from QCD Sum
  Rules}, Phys. Rept. 127 (1985) 1.
\newblock \href {http://dx.doi.org/10.1016/0370-1573(85)90065-1}
  {\path{doi:10.1016/0370-1573(85)90065-1}}.

\bibitem{Colangelo:2000dp}
P.~Colangelo, A.~Khodjamirian, {QCD sum rules, a modern perspective}\href
  {http://arxiv.org/abs/hep-ph/0010175} {\path{arXiv:hep-ph/0010175}}.

\bibitem{Ioffe:2005ym}
B.~L. Ioffe, {QCD at low energies}, Prog. Part. Nucl. Phys. 56 (2006) 232--277.
\newblock \href {http://arxiv.org/abs/hep-ph/0502148}
  {\path{arXiv:hep-ph/0502148}}, \href
  {http://dx.doi.org/10.1016/j.ppnp.2005.05.001}
  {\path{doi:10.1016/j.ppnp.2005.05.001}}.

\bibitem{:2008hx}
B.~Aubert, et~al., {Measurement of the $e^{+} e^{-} \to b \bar{b}$ cross
  section between $\sqrt{s}$ = 10.54-GeV and 11.20-GeV}, Phys. Rev. Lett. 102
  (2009) 012001.
\newblock \href {http://arxiv.org/abs/0809.4120} {\path{arXiv:0809.4120}},
  \href {http://dx.doi.org/10.1103/PhysRevLett.102.012001}
  {\path{doi:10.1103/PhysRevLett.102.012001}}.

\bibitem{Kuhn:2007vp}
J.~H. Kuhn, M.~Steinhauser, C.~Sturm, {Heavy quark masses from sum rules in
  four-loop approximation}, Nucl. Phys. B778 (2007) 192--215.
\newblock \href {http://arxiv.org/abs/hep-ph/0702103}
  {\path{arXiv:hep-ph/0702103}}, \href
  {http://dx.doi.org/10.1016/j.nuclphysb.2007.04.036}
  {\path{doi:10.1016/j.nuclphysb.2007.04.036}}.

\bibitem{Kuhn:2001dm}
J.~H. Kuhn, M.~Steinhauser, {Determination of $\alpha_s$ and heavy quark masses
  from recent measurements of $R(s)$}, Nucl. Phys. B619 (2001) 588--602.
\newblock \href {http://arxiv.org/abs/hep-ph/0109084}
  {\path{arXiv:hep-ph/0109084}}, \href
  {http://dx.doi.org/10.1016/S0550-3213(01)00499-0}
  {\path{doi:10.1016/S0550-3213(01)00499-0}}.

\bibitem{Kuhn:2002zr}
J.~H. Kuhn, M.~Steinhauser, {The impact of sigma(e+ e- --> hadrons)
  measurements at intermediate energies on the parameters of the standard
  model}, JHEP 10 (2002) 018.
\newblock \href {http://arxiv.org/abs/hep-ph/0209357}
  {\path{arXiv:hep-ph/0209357}}.

\bibitem{Chetyrkin:1995ii}
K.~G. Chetyrkin, J.~H. Kuhn, M.~Steinhauser, {Heavy Quark Vacuum Polarisation
  to Three Loops}, Phys. Lett. B371 (1996) 93--98.
\newblock \href {http://arxiv.org/abs/hep-ph/9511430}
  {\path{arXiv:hep-ph/9511430}}, \href
  {http://dx.doi.org/10.1016/0370-2693(95)01593-0}
  {\path{doi:10.1016/0370-2693(95)01593-0}}.

\bibitem{Chetyrkin:1996cf}
K.~G. Chetyrkin, J.~H. Kuhn, M.~Steinhauser, {Three-loop polarization function
  and O(alpha(s)**2) corrections to the production of heavy quarks}, Nucl.
  Phys. B482 (1996) 213--240.
\newblock \href {http://arxiv.org/abs/hep-ph/9606230}
  {\path{arXiv:hep-ph/9606230}}, \href
  {http://dx.doi.org/10.1016/S0550-3213(96)00534-2}
  {\path{doi:10.1016/S0550-3213(96)00534-2}}.

\bibitem{Chetyrkin:1997mb}
K.~G. Chetyrkin, J.~H. Kuhn, M.~Steinhauser, {Heavy quark current correlators
  to O(alpha(s)**2)}, Nucl. Phys. B505 (1997) 40--64.
\newblock \href {http://arxiv.org/abs/hep-ph/9705254}
  {\path{arXiv:hep-ph/9705254}}, \href
  {http://dx.doi.org/10.1016/S0550-3213(97)00481-1}
  {\path{doi:10.1016/S0550-3213(97)00481-1}}.

\bibitem{Boughezal:2006uu}
R.~Boughezal, M.~Czakon, T.~Schutzmeier, {Four-loop tadpoles: Applications in
  QCD}, Nucl. Phys. Proc. Suppl. 160 (2006) 160--164.
\newblock \href {http://arxiv.org/abs/hep-ph/0607141}
  {\path{arXiv:hep-ph/0607141}}, \href
  {http://dx.doi.org/10.1016/j.nuclphysbps.2006.09.041}
  {\path{doi:10.1016/j.nuclphysbps.2006.09.041}}.

\bibitem{Maier:2007yn}
A.~Maier, P.~Maierhofer, P.~Marquard, {Higher Moments of Heavy Quark
  Correlators in the Low Energy Limit at O($\alpha_s^2$)}, Nucl. Phys. B797
  (2008) 218--242.
\newblock \href {http://arxiv.org/abs/0711.2636} {\path{arXiv:0711.2636}},
  \href {http://dx.doi.org/10.1016/j.nuclphysb.2007.12.035}
  {\path{doi:10.1016/j.nuclphysb.2007.12.035}}.

\bibitem{Chetyrkin:2006xg}
K.~G. Chetyrkin, J.~H. Kuhn, C.~Sturm, {Four-loop moments of the heavy quark
  vacuum polarization function in perturbative QCD}, Eur. Phys. J. C48 (2006)
  107--110.
\newblock \href {http://arxiv.org/abs/hep-ph/0604234}
  {\path{arXiv:hep-ph/0604234}}, \href
  {http://dx.doi.org/10.1140/epjc/s2006-02610-y}
  {\path{doi:10.1140/epjc/s2006-02610-y}}.

\bibitem{Boughezal:2006px}
R.~Boughezal, M.~Czakon, T.~Schutzmeier, {Charm and bottom quark masses from
  perturbative QCD}, Phys. Rev. D74 (2006) 074006.
\newblock \href {http://arxiv.org/abs/hep-ph/0605023}
  {\path{arXiv:hep-ph/0605023}}, \href
  {http://dx.doi.org/10.1103/PhysRevD.74.074006}
  {\path{doi:10.1103/PhysRevD.74.074006}}.

\bibitem{Maier:2008he}
A.~Maier, P.~Maierhofer, P.~Marquard, {The second physical moment of the heavy
  quark vector correlator at O($\alpha_s^3$)}, Phys. Lett. B669 (2008) 88--91.
\newblock \href {http://arxiv.org/abs/0806.3405} {\path{arXiv:0806.3405}},
  \href {http://dx.doi.org/10.1016/j.physletb.2008.09.041}
  {\path{doi:10.1016/j.physletb.2008.09.041}}.

\bibitem{Maier:2009fz}
A.~Maier, P.~Maierhofer, P.~Marquard, A.~V. Smirnov, {Low energy moments of
  heavy quark current correlators at four loops}, Nucl. Phys. B824 (2010)
  1--18.
\newblock \href {http://arxiv.org/abs/0907.2117} {\path{arXiv:0907.2117}},
  \href {http://dx.doi.org/10.1016/j.nuclphysb.2009.08.011}
  {\path{doi:10.1016/j.nuclphysb.2009.08.011}}.

\bibitem{Kiyo:2009gb}
Y.~Kiyo, A.~Maier, P.~Maierhofer, P.~Marquard, {Reconstruction of heavy quark
  current correlators at O($\alpha_s^3$)}, Nucl. Phys. B823 (2009) 269--287.
\newblock \href {http://arxiv.org/abs/0907.2120} {\path{arXiv:0907.2120}},
  \href {http://dx.doi.org/10.1016/j.nuclphysb.2009.08.010}
  {\path{doi:10.1016/j.nuclphysb.2009.08.010}}.

\bibitem{Hoang:2008qy}
A.~H. Hoang, V.~Mateu, S.~Mohammad~Zebarjad, {Heavy Quark Vacuum Polarization
  Function at $O(alpha_s^2)$ and $O(alpha_s^3)$}, Nucl. Phys. B813 (2009)
  349--369.
\newblock \href {http://arxiv.org/abs/0807.4173} {\path{arXiv:0807.4173}},
  \href {http://dx.doi.org/10.1016/j.nuclphysb.2008.12.005}
  {\path{doi:10.1016/j.nuclphysb.2008.12.005}}.

\bibitem{Greynat:2010kx}
D.~Greynat, S.~Peris, {Resummation of Threshold, Low- and High-Energy
  Expansions for Heavy-Quark Correlators}, Phys. Rev. D82 (2010) 034030.
\newblock \href {http://arxiv.org/abs/1006.0643} {\path{arXiv:1006.0643}},
  \href {http://dx.doi.org/10.1103/PhysRevD.82.034030}
  {\path{doi:10.1103/PhysRevD.82.034030}}.

\bibitem{Besson:1984bd}
D.~Besson, et~al., {Observation of New Structure in the e+ e- Annihilation
  Cross-Section Above B anti-B Threshold}, Phys. Rev. Lett. 54 (1985) 381.
\newblock \href {http://dx.doi.org/10.1103/PhysRevLett.54.381}
  {\path{doi:10.1103/PhysRevLett.54.381}}.

\bibitem{McNeile:2010ji}
C.~McNeile, C.~T.~H. Davies, E.~Follana, K.~Hornbostel, G.~P. Lepage,
  {High-Precision c and b Masses, and QCD Coupling from Current-Current
  Correlators in Lattice and Continuum QCD}, Phys. Rev. D82 (2010) 034512.
\newblock \href {http://arxiv.org/abs/1004.4285} {\path{arXiv:1004.4285}},
  \href {http://dx.doi.org/10.1103/PhysRevD.82.034512}
  {\path{doi:10.1103/PhysRevD.82.034512}}.

\bibitem{Narison:2010cg}
S.~Narison, {Gluon condensates and c, b quark masses from quarkonia ratios of
  moments}\href {http://arxiv.org/abs/1004.5333} {\path{arXiv:1004.5333}}.

\bibitem{Chetyrkin:2000yt}
K.~G. Chetyrkin, J.~H. Kuhn, M.~Steinhauser, {RunDec: A Mathematica package for
  running and decoupling of the strong coupling and quark masses}, Comput.
  Phys. Commun. 133 (2000) 43--65.
\newblock \href {http://arxiv.org/abs/hep-ph/0004189}
  {\path{arXiv:hep-ph/0004189}}, \href
  {http://dx.doi.org/10.1016/S0010-4655(00)00155-7}
  {\path{doi:10.1016/S0010-4655(00)00155-7}}.

\bibitem{Sturm:2008eb}
C.~Sturm, {Moments of Heavy Quark Current Correlators at Four-Loop Order in
  Perturbative QCD}, JHEP 09 (2008) 075.
\newblock \href {http://arxiv.org/abs/0805.3358} {\path{arXiv:0805.3358}},
  \href {http://dx.doi.org/10.1088/1126-6708/2008/09/075}
  {\path{doi:10.1088/1126-6708/2008/09/075}}.

\bibitem{Allison:2008xk}
I.~Allison, et~al., {High-Precision Charm-Quark Mass from Current-Current
  Correlators in Lattice and Continuum QCD}, Phys. Rev. D78 (2008) 054513.
\newblock \href {http://arxiv.org/abs/0805.2999} {\path{arXiv:0805.2999}},
  \href {http://dx.doi.org/10.1103/PhysRevD.78.054513}
  {\path{doi:10.1103/PhysRevD.78.054513}}.

\end{thebibliography}
