found: The Passionate stranger [MP] 1957:credits (original screen play by Sydney Box)
found: The Illustrated who's who of the cinema, 1983:p. 53 (Box, Sydney; b. 1907 in Beckenham, Kent, England; d. 1983; playwright, screenwriter, film producer, television executive)
found: The Author's & writer's who's who, 1972:p. 90-91 (Box, Sydney; author)
found: LC data base, 4/26/94(hdg.: Box, Sydney, 1907- )
found: The lion that lost its way and other cautionary tales of the show business jungle, 2005:CIP t.p. (Sydney Box) data sheet (b. April 29, 1907)
found: IMDb, Mar. 20, 2007(Sydney Box; b. Apr. 29, 1907, Beckenham, England; d. May 25, 1983, Perth, W.A.)
found: The black-out book, 2009:t.p. (Evelyn August) p.[ix-xi] (Evelyn August was a joint pseud. of Sydney and Muriel Box; Sydney Box, b. 1907, Beckenham, Kent; d. 25 May 1983 and Muriel Box, née Violette Muriel Baker, b. 22 Sept. 1905, Tolworth, Surrey; d. 19 May 1991)
found: BL database, 19 Nov. 2010(hdg.: Box, Frank Sydney; usage: Sydney Box)