  In this talk we discuss some aspects of the analytical calculation of energy
correlations in electron-positron annihilation at a next-to-leading order in
QCD. Our primary focus is on the most difficult task: the calculation of master
integrals for real-emission contributions, which are functions of two
dimensionless variables and the dimensional regulator. We use a method of
differential equations and their so-called epsilon-form which is constructed
with the help of the Fuchsia program based on Lee's algorithm.
