  
  
  [1XReferences[101X
  
  [[20XBR08[120X] [16XBarakat, M. and Robertz, D.[116X, [17Xhomalg project[117X (2003-2008), ((http://wwwb.math.rwth-aachen.de/homalg)).
  
  [[20XGör08a[120X] [16XGörtzen, S.[116X, [17XSimplicial Cohomology of Orbifolds[117X, Master's thesis, RWTH Aachen University (2008), ((in preparation)).
  
  [[20XGör08b[120X] [16XGörtzen, S.[116X, [17XWallpaper Group Cohomology[117X (2008), ((http://wwwb.math.rwth-aachen.de/goertzen/)).
  
  [[20XMP99[120X] [16XMoerdijk, I. and Pronk, D. A.[116X, [17XSimplicial cohomology of orbifolds[117X, [18XIndag. Math. (N.S.)[118X, [19X10[119X, 2 (1999), 269--293.
  
  
  
  [32X
