||Lyles, William H.. Dell Paperbacks, 1942 to Mid-1962. A Catalog-Index. Greenwood Press 
||A complete source of information on Dell publications from the beginning into the sixties. Includes print sizes and issue dates; the original source of any artist information on early Dell releases. Still in print and very valuable. Issue dates and print runs are based on Western Printers and Dell's contemporary records. Printing dates may differ from recorded publication date.
||Moore, Ruth. Bibliography of Erle Stanley Gardner. [in] The Case of the Real Perry Mason by Dorothy B. Hughes. William Morrow 1978
||The bibliography was done by one of Gardner's long-time secretaries. Occasionally there is a discrepancy on the date of the initial printing for a Dell paperback when compared with Lyles; this can be expected to be the variance between official publication date and actual printing date. Such variances are explicitly recorded in early Pocket Books paperbacks.
||Cook, Michael L.. Murder By Mail. Inside the Mystery Book Clubs. With Complete Checklist. Revised, expanded and updated edition. Bowling Green University Popular Press [c.1983]
||The main source of book club information; comprehensive into the eighties (and so does not cover the last years of the major clubs).
||Dsavis, Kenneth C.. Two-Bit Culture. The Paperbacking of America. Houghton Mifflin, 1984
||A history of the mass market publishing industry in America from the beginnings though the early eighties; excellent cultural history; bibliographical details are incidental but interesting.
||Cole, John Y. . Books in Action. The Armed Services Editions.. Library of Congress, 1984.
||History of their production, and a comprehensive list of all Armed Services Editions, with information on their sequence of production and distribution.
||Flanagan, Graeme. Australian Vintage Paperback Guide. Gryphon Books, 1994
||Publication lists of Austraian paperback publishes - mass market and digest - along with reproductions, monochrome, of selected covers.
||Barling, Chris. "The Horwitz Penguins". The Penguin Collector, December 1996. pp. 40-42.
||Article in the Penguin Collector, published by the Penguin Collectors' Society, with background and a complete list of all the Horwitz penguins. The Horwitz Penguins were (or are) notable for their garish covers.
|Scott & Maynard
||Scott, Art and Maynard, Dr. Wallace. The Paperback Covers of Robert McGinnis.. [Boston] Pond Press [c.2001].
||The authority for nearly all of the Robert McGinnis attributions in the Gardner bibliography. Occasionally their listings omit a duplicate edition sharing a cover.
||Baines, Phil. Penguin by Design. A Cover Story 1935-2005.. Penguin Books [c.2005]
||Mysteries make up a tiny percentage of Penguin covers, but there is interesting disussion of the "Marber Grid" etc.
|UK Service Editions
||A detailed reference for UK Service Editions from a variety of publishers.
||A checklist of Guild Books, with background informaiton.
|Penguin First Editions
||A comprehensive list of Penguin First Editions, with cover images and print information. Does not include information on subsequent printings or covers.
|Detective Book Club
||An online resource on the Detective Book Club. Includes information from Cook's Murder by Mail, and carries it forward until the end of the club. NOW OFFLINE.
||UK-based online retailer with an extensive inventory of vintage paperpacks; very large Erle Standley Gardner selection. They have very generously allowed use of images selected from their website.
||UK-based online retail, with a good selection of less common paperback editions, mostly at abebooks.co.uk. They have very generously allowed use of images selected from their website.
||Listing of Perry Mason television episodes.
|Bar Harbor Bookshop
||Antiquarian bookseller with an impressive offering of Erle Stanley Gardner first editions.
||The PAN Paperback Collectors Site. An excellent source for information on Pan Paperbacks, including very interesting information on the artists that produced the covers. There is even archival material relating to the creation of some of the covers.