APA-referens (7:e uppl.)

Graf, A. B. (1981). Tropica: Color cyclopedia of exotic plants and trees for warm-region horticulture--in cool climate the summer garden or sheltered indoors (2nd ed., rev. and enl.). Roehrs Co.

Chicago-referens (17:e uppl.)

Graf, Alfred Byrd. Tropica: Color Cyclopedia of Exotic Plants and Trees for Warm-region Horticulture--in Cool Climate the Summer Garden or Sheltered Indoors. 2nd ed., rev. and enl. East Rutherford, N.J: Roehrs Co, 1981.

MLA-referens (9:e uppl.)

Graf, Alfred Byrd. Tropica: Color Cyclopedia of Exotic Plants and Trees for Warm-region Horticulture--in Cool Climate the Summer Garden or Sheltered Indoors. 2nd ed., rev. and enl. Roehrs Co, 1981.