1. A weak difference set construction for higher dimensional designs;de Launey;Designs Codes Cryptography,1993
2. A Course in Homological Algebra;Hilton,1971
3. Cocyclic development of designs;Horadam;J. Algebraic Combin.,1993
4. Presentation of Groups;Johnson,1976
5. Projective Representations of Finite Groups;Karpilovsky,1985