Sisam, J. (1947). The use of aerial survey in forestry and agriculture (6th.). Imperial forestry bureau and pastures and field crops.
Chicago-referens (17:e uppl.)Sisam, J.W.B. The Use of Aerial Survey in Forestry and Agriculture. 6th. Aberystwyth: Imperial forestry bureau and pastures and field crops, 1947.
MLA-referens (9:e uppl.)Sisam, J.W.B. The Use of Aerial Survey in Forestry and Agriculture. 6th. Imperial forestry bureau and pastures and field crops, 1947.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.