Dunn, Richard. "A comparison of total and soluble nitrogen, phosphorus, potassium, calcium, and magnesium found in the leaves of tomato plants grown under various levels of nitrogen, phosphorus, and potassium in \"Haydite\" media /." Doctoral dissertation, Ohio State University, 1953. http://rave.ohiolink.edu/etdc/view?acc_num=osu1486471132853926Chicago Manual of Style (17th edition)