CROCKETT, J. U. Lawns and ground covers: The time-life encyclopedia of gardening. Time-Life Books Alexandria.
Chicago-referens (17:e uppl.)CROCKETT, James Underwood. Lawns and Ground Covers: The Time-life Encyclopedia of Gardening. Time-Life Books Alexandria.
MLA-referens (8:e uppl.)CROCKETT, James Underwood. Lawns and Ground Covers: The Time-life Encyclopedia of Gardening. Time-Life Books Alexandria.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.