TY  - BOOK
AU  - Levens,A.S.
AU  - Edstrom,Alfred E.
TI  - Problems in engineering drawing,: series 5-
U1  - 744.422076 
PY  - 1960///
CY  - New York, London
PB  - McGraw-Hill book company, inc.
KW  - Mechanical drawing
ER  -