Gilbertson, H. W. (1948). Educational exhibits: How to prepare and use them; a manual for extension workers. U.S. Govt. Print. Off..
Chicago-referens (17:e uppl.)Gilbertson, Henry Walter. Educational Exhibits: How to Prepare and Use Them; a Manual for Extension Workers. Washington: U.S. Govt. Print. Off., 1948.
MLA-referens (8:e uppl.)Gilbertson, Henry Walter. Educational Exhibits: How to Prepare and Use Them; a Manual for Extension Workers. U.S. Govt. Print. Off., 1948.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.