1. Etale Homotopy;Artin,1986
2. Homotopy Limits, Completions and Localizations;Bousfield,1972
3. Conditionally convergent spectral sequences;Boardman,1999
4. Strong homology and the proper forcing axiom;Dow;Proc. Am. Math. Soc.,1989
5. Categories and Sheaves;Kashiwara,2006