TY  - GEN
AU  - Engen, Henry Van [et al.]
TI  - Seeing through mathematics
PY  - 1967///
CY  - Illinois
PB  - Scott Foresman
N1  - 010175-v.1, 010176-v.2, 010177-v.3 (508 p.; 528 p.; 539 p.)
ER  -