Paperback Library, Inc.
260 Park Avenue South
New York, NY 10010
From
imdb.com:
Founded as an independent publisher of paperback books in 1961 in New York City, N.Y., USA. Sometime in the late 1960s it became a division of Coronet Communications. By 1972 it had been acquired by Warner Communications, after which books were published as by Warner Paperback Library.