Schocken Paperbacks

ISBN format: 0-8052-0xxx-c

The SB- prefix falls off sometime around the late SB 600s in the late 1970s and is replaced with 0xxx-c on the spine. At some point in the 1980s, it looks like this spine number is left off again. I'm stopping the series at the 1987 acquisition of Schocken by Random House, which took effect with the first titles published by Schocken in 1988, although it of course continued on numerically up to and well past 1000 if you consider the number in the ISBN.

Schocken Paperbacks: New Quality Line, PW, Jan. 16, 1961, at 99.