\begin{thebibliography}{10}
\providecommand{\url}[1]{\texttt{#1}}
\providecommand{\urlprefix}{URL }
\providecommand{\eprint}[2][]{\url{#2}}

\bibitem{Novikov:1977dq}
V.~A. Novikov, et~al.
\newblock \emph{Phys. Rept.}, 41:1--133, 1978.

\bibitem{Reinders:1984sr}
L.~J. Reinders, H.~Rubinstein, S.~Yazaki.
\newblock \emph{Phys. Rept.}, 127:1, 1985.

\bibitem{Colangelo:2000dp}
P.~Colangelo, A.~Khodjamirian.
\newblock 2000.
\newblock \eprint{hep-ph/0010175}.

\bibitem{Ioffe:2005ym}
B.~L. Ioffe.
\newblock \emph{Prog. Part. Nucl. Phys.}, 56:232--277, 2006.
\newblock \eprint{hep-ph/0502148}.

\bibitem{Chetyrkin:1995ii}
K.~G. Chetyrkin, J.~H. {K\"uhn}, M.~Steinhauser.
\newblock \emph{Phys. Lett.}, B371:93--98, 1996.
\newblock \eprint{hep-ph/9511430}.

\bibitem{Chetyrkin:1996cf}
K.~G. Chetyrkin, J.~H. {K\"uhn}, M.~Steinhauser.
\newblock \emph{Nucl. Phys.}, B482:213--240, 1996.
\newblock \eprint{hep-ph/9606230}.

\bibitem{Chetyrkin:1997mb}
K.~G. Chetyrkin, J.~H. {K\"uhn}, M.~Steinhauser.
\newblock \emph{Nucl. Phys.}, B505:40--64, 1997.
\newblock \eprint{hep-ph/9705254}.

\bibitem{Boughezal:2006uu}
R.~Boughezal, M.~Czakon, T.~Schutzmeier.
\newblock \emph{Nucl. Phys. Proc. Suppl.}, 160:160--164, 2006.
\newblock \eprint{hep-ph/0607141}.

\bibitem{Maier:2007yn}
A.~Maier, P.~{Maierh\"ofer}, P.~Marquard.
\newblock \emph{Nucl. Phys.}, B797:218--242, 2008.
\newblock \eprint{arXiv 0711.2636}.

\bibitem{Sturm:2008eb}
C.~Sturm.
\newblock \emph{JHEP}, 09:075, 2008.
\newblock \eprint{arXiv 0805.3358}.

\bibitem{Boughezal:2006px}
R.~Boughezal, M.~Czakon, T.~Schutzmeier.
\newblock \emph{Phys. Rev.}, D74:074006, 2006.
\newblock \eprint{hep-ph/0605023}.

\bibitem{Chetyrkin:2006xg}
K.~G. Chetyrkin, J.~H. {K\"uhn}, C.~Sturm.
\newblock \emph{Eur. Phys. J.}, C48:107--110, 2006.
\newblock \eprint{hep-ph/0604234}.

\bibitem{Maier:2008he}
A.~Maier, P.~{Maierh\"ofer}, P.~Marquard.
\newblock \emph{Phys. Lett.}, B669:88--91, 2008.
\newblock \eprint{arXiv 0806.3405}.

\bibitem{Maier:2009}
A.~Maier, P.~{Maierh\"ofer}, P.~Marquard, A.~V. Smirnov.
\newblock 2009.
\newblock \eprint{arXiv 0907.2117}.

\bibitem{Hoang:2000yr}
A.~H. Hoang, et~al.
\newblock \emph{Eur. Phys. J. direct}, C2:1, 2000.
\newblock \eprint{hep-ph/0001286}.

\bibitem{Penin:1998ik}
A.~A. Penin, A.~A. Pivovarov.
\newblock \emph{Nucl. Phys.}, B550:375--396, 1999.
\newblock \eprint{hep-ph/9810496}.

\bibitem{Beneke:1999fe}
M.~Beneke, A.~Signer.
\newblock \emph{Phys. Lett.}, B471:233--243, 1999.
\newblock \eprint{hep-ph/9906475}.

\bibitem{Pineda:2006ri}
A.~Pineda, A.~Signer.
\newblock \emph{Nucl. Phys.}, B762:67--94, 2007.
\newblock \eprint{hep-ph/0607239}.

\bibitem{Harlander:1997xa}
R.~Harlander, M.~Steinhauser.
\newblock \emph{Phys. Rev.}, D56:3980--3990, 1997.
\newblock \eprint{hep-ph/9704436}.

\bibitem{Chetyrkin:1997qi}
K.~G. Chetyrkin, R.~Harlander, J.~H. {K\"uhn}, M.~Steinhauser.
\newblock \emph{Nucl. Phys.}, B503:339--353, 1997.
\newblock \eprint{hep-ph/9704222}.

\bibitem{Harlander:1997kw}
R.~Harlander, M.~Steinhauser.
\newblock \emph{Eur. Phys. J.}, C2:151--158, 1998.
\newblock \eprint{hep-ph/9710413}.

\bibitem{Baikov:2004ku}
P.~A. Baikov, K.~G. Chetyrkin, J.~H. {K\"uhn}.
\newblock \emph{Nucl. Phys. Proc. Suppl.}, 135:243--246, 2004.

\bibitem{Baikov:2009uw}
P.~A. Baikov, K.~G. Chetyrkin, J.~H. {K\"uhn}.
\newblock 2009.
\newblock \eprint{arXiv 0906.2987}.

\bibitem{Gorishnii:1991vf}
S.~G. Gorishnii, A.~L. Kataev, S.~A. Larin.
\newblock \emph{Phys. Lett.}, B259:144--150, 1991.

\bibitem{Surguladze:1991tg}
L.~R. Surguladze, M.~A. Samuel.
\newblock \emph{Phys. Rev. Lett.}, 66:560--563, 1991 Erratum-ibid. 66, 2416
  (1991).

\bibitem{Chetyrkin:1990kr}
K.~G. Chetyrkin, J.~H. {K\"uhn}.
\newblock \emph{Phys. Lett.}, B248:359--364, 1990.

\bibitem{Chetyrkin:1996hm}
K.~G. Chetyrkin, J.~H. {K\"uhn}.
\newblock \emph{Phys. Lett.}, B406:102--109, 1997.
\newblock \eprint{hep-ph/9609202}.

\bibitem{Chetyrkin:2000zk}
K.~G. Chetyrkin, R.~V. Harlander, J.~H. {K\"uhn}.
\newblock \emph{Nucl. Phys.}, B586:56--72, 2000.
\newblock \eprint{hep-ph/0005139}.

\bibitem{Baikov:2008jh}
P.~A. Baikov, K.~G. Chetyrkin, J.~H. {K\"uhn}.
\newblock \emph{Phys. Rev. Lett.}, 101:012002, 2008.
\newblock \eprint{arXiv 0801.1821}.

\bibitem{Baikov:2005rw}
P.~A. Baikov, K.~G. Chetyrkin, J.~H. {K\"uhn}.
\newblock \emph{Phys. Rev. Lett.}, 96:012003, 2006.
\newblock \eprint{hep-ph/0511063}.

\bibitem{Pivovarov:1991bi}
A.~A. Pivovarov.
\newblock \emph{Nuovo Cim.}, A105:813--826, 1992.

\bibitem{Pivovarov:1991rh}
A.~A. Pivovarov.
\newblock \emph{Z. Phys.}, C53:461--464, 1992.
\newblock \eprint{hep-ph/0302003}.

\bibitem{LeDiberder:1992te}
F.~Le~Diberder, A.~Pich.
\newblock \emph{Phys. Lett.}, B286:147--152, 1992.

\bibitem{Kallen:1955fb}
A.~O.~G. Kallen, A.~Sabry.
\newblock \emph{Kong. Dan. Vid. Sel. Mat. Fys. Med.}, 29N17:1--20, 1955.

\bibitem{Baker:1975}
G.~A. Baker.
\newblock \emph{Essentials of Pad\'e Approximants}.
\newblock Academic Press, Inc., 1975.

\bibitem{Broadhurst:1993mw}
D.~J. Broadhurst, J.~Fleischer, O.~V. Tarasov.
\newblock \emph{Z. Phys.}, C60:287--302, 1993.
\newblock \eprint{hep-ph/9304303}.

\bibitem{Fleischer:1994ef}
J.~Fleischer, O.~V. Tarasov.
\newblock \emph{Z. Phys.}, C64:413--426, 1994.
\newblock \eprint{hep-ph/9403230}.

\bibitem{Broadhurst:1994qj}
D.~J. Broadhurst, et~al.
\newblock \emph{Phys. Lett.}, B329:103--110, 1994.
\newblock \eprint{hep-ph/9403274}.

\bibitem{Baikov:1995ui}
P.~A. Baikov, D.~J. Broadhurst.
\newblock 1995.
\newblock \eprint{hep-ph/9504398}.

\bibitem{Chetyrkin:1998ix}
K.~G. Chetyrkin, R.~Harlander, M.~Steinhauser.
\newblock \emph{Phys. Rev.}, D58:014012, 1998.
\newblock \eprint{hep-ph/9801432}.

\bibitem{Hoang:2008qy}
A.~H. Hoang, V.~Mateu, S.~Mohammad~Zebarjad.
\newblock \emph{Nucl. Phys.}, B813:349--369, 2009.
\newblock \eprint{arXiv 0807.4173}.

\bibitem{Baikov:prel}
P.~Baikov, K.~Chetyrkin, J.~{K\"uhn}.
\newblock In preparation.

\bibitem{Chetyrkin:prel}
K.~Chetyrkin, R.~Harlander.
\newblock In preparation.

\bibitem{Caswell:1985ui}
W.~E. Caswell, G.~P. Lepage.
\newblock \emph{Phys. Lett.}, B167:437, 1986.

\bibitem{Bodwin:1994jh}
G.~T. Bodwin, E.~Braaten, G.~P. Lepage.
\newblock \emph{Phys. Rev.}, D51:1125--1171, 1995.
\newblock \eprint{hep-ph/9407339}.

\bibitem{Czarnecki:1997vz}
A.~Czarnecki, K.~Melnikov.
\newblock \emph{Phys. Rev. Lett.}, 80:2531--2534, 1998.
\newblock \eprint{hep-ph/9712222}.

\bibitem{Beneke:1997jm}
M.~Beneke, A.~Signer, V.~A. Smirnov.
\newblock \emph{Phys. Rev. Lett.}, 80:2535--2538, 1998.
\newblock \eprint{hep-ph/9712302}.

\bibitem{Marquard:2006qi}
P.~Marquard, J.~H. Piclum, D.~Seidel, M.~Steinhauser.
\newblock \emph{Nucl. Phys.}, B758:144--160, 2006.
\newblock \eprint{hep-ph/0607168}.

\bibitem{Marquard:2009bj}
P.~Marquard, J.~H. Piclum, D.~Seidel, M.~Steinhauser.
\newblock \emph{Phys. Lett.}, B678:269--275, 2009.
\newblock \eprint{arXiv 0904.0920}.

\bibitem{Kniehl:2006qw}
B.~A. Kniehl, A.~Onishchenko, J.~H. Piclum, M.~Steinhauser.
\newblock \emph{Phys. Lett.}, B638:209--213, 2006.
\newblock \eprint{hep-ph/0604072}.

\bibitem{Beneke:1999qg}
M.~Beneke, A.~Signer, V.~A. Smirnov.
\newblock \emph{Phys. Lett.}, B454:137--146, 1999.
\newblock \eprint{hep-ph/9903260}.

\bibitem{Larin:1994va}
S.~A. Larin, T.~van Ritbergen, J.~A.~M. Vermaseren.
\newblock \emph{Nucl. Phys.}, B438:278--306, 1995.
\newblock \eprint{hep-ph/9411260}.

\bibitem{Chetyrkin:1997un}
K.~G. Chetyrkin, B.~A. Kniehl, M.~Steinhauser.
\newblock \emph{Nucl. Phys.}, B510:61--87, 1998.
\newblock \eprint{hep-ph/9708255}.

\end{thebibliography}
