Putnam et al., 1990. In: Alternative Field Crop Manual, University of Wisconsin-Exension, Cooperative Extension
Document reference
Putnam, D. H. ; Oplinger, E. S. ; Hicks, D. R. ; Durgan, B. R. ; Noetzel, D. M. ; Meronuck, R. A. ; Doll, J. D. ; Schulte, E. E., 1990. Sunflower. In: Alternative Field Crop Manual, University of Wisconsin-Exension, Cooperative Extension