166 PW 2048 (Nov. 20, 1954):
GROVE PRESS will put many of its new titles and re-issues into lower priced paperbound editions starting early in 1955, according to Barney Rosset, publisher and editor. “All of our paperbound editions will be exclusive Grove Press titles and will not bear any special series name,” he explains. “They will contain the full text of the original hardbound editions and will have virtually the same size and format. For those readers who prefer more durable covers we will continue to publish hardbound editions of all our titles. We will also bring out a list of new titles in hardbound editions only.” Prices of the first twelve paperbounds will range from $1 to $1.50.
166 PW 2348 (Dec. 18, 1954):
EVERGREEN BOOKS is the name chosen by Grove Press for the paperbound editions which it will begin issuing early in 1955, editions both of previously published Grove hard-cover titles, and of new Grove titles published simultaneously in hard covers with the paper editions (PW, November 20). Prices, sizes and formats will vary according to those of the hard-cover editions. Grove will emphasize Evergreen Editions in its 1955 promotion and ads, which will include a two-page spread in PW, and increased space in the New York Times and major literary periodicals.
Ad, 167 PW 290-291 (Jan. 22, 1955) (two-page spread announcing the first 10 titles in the Evergreen Books line, with photos of the front covers).
Evergreen to Launch Paperback Art Series, PW, Apr. 20, 1959, at 30 (announcing the Evergreen Gallery Books, which didn't have their own series numbers; instead, they were part of the main Evergreen Books series.)
http://www.bu.edu/partisanreview/books/PR1955V22N2/HTML/files/assets/basic-html/index.html#150 -- ad announcing series in Partisan Review (vol. 22)
https://archive.org/details/psychotherapyins00vses/page/n225 -- lists up to E-338 in back
https://i.ebayimg.com/images/g/MaQAAOSwzrlbbP0Q/s-l1600.jpg -- spines of Evergreen Review 1-31
https://realitystudio.org/bibliographic-bunker/evergreen-review-archive/ -- archive of Evergreen Review covers 1-96
Early ad for E-25 to E-32: http://www.bu.edu/partisanreview/books/PR1956V23N2/HTML/files/assets/basic-html/index.html#151