\chapcontents {1}{Cohomology}{3}
\seccontents {1.1}{CHR} {4}
\seccontents {1.2}{SchurMultiplier} {4}
\seccontents {1.3}{CoveringGroup} {4}
\seccontents {1.4}{FirstCohomologyDimension} {4}
\seccontents {1.5}{SecondCohomologyDimension} {4}
\seccontents {1.6}{SplitExtensionCHR} {5}
\seccontents {1.7}{NonsplitExtension} {5}
\seccontents {1.8}{CalcPres} {5}
\seccontents {1.9}{PermRep} {5}
\seccontents {1.10}{Further Information} {6}