TY  - DATA
AU  - Heller, Alex
TI  - Homotopy theories 
T2  - Memoirs of the American Mathematical Society, 
SN  - 9781470408039 (online)
PY  - 1988///
CY  - Providence, R.I., USA
PB  - American Mathematical Society
UR  - http://www.ams.org/memo/0383
ER  -