Não informado. (2018). Research Report. Virginia Agricultural Experiment Station, Virginia Polytechnic Institute.
Chicago-referens (17:e uppl.)Não informado. Research Report. Blacksburg, Va: Virginia Agricultural Experiment Station, Virginia Polytechnic Institute, 2018.
MLA-referens (8:e uppl.)Não informado. Research Report. Virginia Agricultural Experiment Station, Virginia Polytechnic Institute, 2018.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.