TY  - BOOK
AU  - Massey William S
TI  - Algebraic topology :  An introduction   
T2  - Graduate Texts in Mathematics, 56
SN  - 9780387902715
U1  - B316, K7 
PY  - 1967///
CY  - New York
PB  - Springer-Verlag         
KW  - Economics
N1  - Appendix : P 243-258
ER  -