Washington Post, May 11, 1999 (Shel Silverstein, age 66, native of Chicago, found dead in home at Key West, Fla., May 10, 1999)
Contemp. authors, Mar. 31, 2004 (Shel(by) Silverstein; b. Sept. 25, 1930, Chicago, Ill.; d. May 8, 1999, Key West, Fla.)
Biog. resource center, Mar. 31, 2004 (Silverstein, Shel(by) (American cartoonist, 1932-c. 1999); Authors and Artists for Young Adults, 2001 (Shel Silverstein; b. Sept. 25, 1930, Chicago, Ill.; d. May 10, 1999, Key West, Fla.); Encyclopedia of World Biography Supplement, 1999 (Shel Silverstein; b. 1930, Chicago, Ill.; d. May 10, 1999, Key West, Fla.); Marquis Who's Who (b. 1932, Chicago, Ill.; d. May 10, 1999)
Wikipedia WWW site, October 8, 2014 (Shel Silverstein (September 25, 1930-May 10, 1999); American author of childrens books, cartoonist, singer-songwriter, poet, screenwriter)