PHYLLIS HARTNOLL and PETER FOUND. "Bergman, Hjalmar Frederik." The Concise Oxford Companion to the Theatre. 1996. Encyclopedia.com. 5 Jul. 2009 <http://www.encyclopedia.com>.
PHYLLIS HARTNOLL and PETER FOUND. "Bergman, Hjalmar Frederik." The Concise Oxford Companion to the Theatre. 1996. Encyclopedia.com. (July 5, 2009). http://www.encyclopedia.com/doc/1O79-BergmanHjalmarFrederik.html
PHYLLIS HARTNOLL and PETER FOUND. "Bergman, Hjalmar Frederik." The Concise Oxford Companion to the Theatre. 1996. Retrieved July 05, 2009 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O79-BergmanHjalmarFrederik.html