http://en.wikipedia.org/wiki/Alfredo_Kraus "This article needs additional citations for verification."
However, http://en.wikipedia.org/wiki/Wikipedia:Citing_sources doesn't say where the citations should be sent. Here are some books in date order where published biographies of Alfredo Kraus appear, but there is no "[edit] Bibliography" section on the page where they can be added. If they are needed, I will be happy to send photocopies of these articles to the author(s) of this Wikipedia entry.
Rosenthal, Harold and John Warrack, 1979, p. 265 The Concise Oxford Dictionary of Opera http://www.folklib.net/index/discog/bibliog7.shtml#ko
Hamilton, David, 1987, p. 182 The Metropolitan Opera Encyclopedia: A Comprehensive Guide to the World of Opera http://www.folklib.net/index/discog/bibliog7.shtml#kq
Warrack, John and Ewan West, 1996, p. 271 The Concise Oxford Dictionary of Opera http://www.folklib.net/index/discog/bibliog7.shtml#kp
Sadie, Stanley and John Tyrrell, 2001, Vol. 13, p. 874-5 The New Grove Dictionary of Music and Musicians http://www.folklib.net/index/discog/bibliog.shtml#km ____________________________________________________________ Doug Henkle - mailto:henkle@pobox.com P.O. Box 1447, Oshkosh, WI 54903-1447
http://www.folklib.net/opera/singers.shtml FolkLib Index - Opera Singer Index