1. Homotopy Limits, Completions and Localisations;Bousfield,1972
2. Abstract homotopy theory and generalized sheaf cohomology;Brown;Trans. Amer. Math. Soc.,1973
3. Algebraic K-theory as generalized sheaf cohomology;Brown,1973
4. On catn-groups and homotopy types;Bullejos;J. Pure Appl. Algebra,1993
5. S.E. Crans and I. Moerdijk, On simplicial groupoids, in preparation.