Philbrick, J. H., & Philbrick, H. (1971). Organic gardening for health and nutrition: An introduction to the method of bio-dynamic gardening inaugurated by Rudolf Steiner. Castle Books.
Chicago-referens (17:e uppl.)Philbrick, John H., och Helen Philbrick. Organic Gardening for Health and Nutrition: An Introduction to the Method of Bio-dynamic Gardening Inaugurated by Rudolf Steiner. New York: Castle Books, 1971.
MLA-referens (8:e uppl.)Philbrick, John H., och Helen Philbrick. Organic Gardening for Health and Nutrition: An Introduction to the Method of Bio-dynamic Gardening Inaugurated by Rudolf Steiner. Castle Books, 1971.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.