Não informado. (1889). Bulletin of the Virginia Agricultural Experiment Station. Virginia Polytechnic Institute.
Chicago-referens (17:e uppl.)Não informado. Bulletin of the Virginia Agricultural Experiment Station. Blacksburg, Va: Virginia Polytechnic Institute, 1889.
MLA-referens (8:e uppl.)Não informado. Bulletin of the Virginia Agricultural Experiment Station. Virginia Polytechnic Institute, 1889.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.