TY  - BOOK
AU  - Marks,Robert W.
TI  - Simplifying set theory: a programmed text 
T2  - A unifact book. SU4
AV  - BF 175 M346s 1966
PY  - 1966///]
CY  - New York
PB  - Bantam Books
KW  - Set (Psychology)
ER  -