Reference Lorenz, Oscar, and Donald Maynard. Knott's Handbook for Vegetable Growers. NY: John Wiley & Sons, 1988. Novak, Joseph R. Lecture supplement. Seeds. 1961. The Yearbook of Agriculture. U.S. Government Printing Office. Seeds Index
Lorenz, Oscar, and Donald Maynard. Knott's Handbook for Vegetable Growers. NY: John Wiley & Sons, 1988.
Novak, Joseph R. Lecture supplement.
Seeds. 1961. The Yearbook of Agriculture. U.S. Government Printing Office.