APA
Gustafson R., . (1958). Carryover Levels for Grains: A Method for determining amounts that are optimal under specified conditions. : United States Department of Agriculture,Washington.
Chicago
Gustafson RL, . 1958. Carryover Levels for Grains: A Method for determining amounts that are optimal under specified conditions. : United States Department of Agriculture,Washington.
Harvard
Gustafson R., . (1958). Carryover Levels for Grains: A Method for determining amounts that are optimal under specified conditions. : United States Department of Agriculture,Washington.
MLA
Gustafson RL, . Carryover Levels for Grains: A Method for determining amounts that are optimal under specified conditions. : United States Department of Agriculture,Washington. 1958.