1. ANNAU, E, Concerning the significance of fumaric acid for animal tissue respiration., HOPPE-SEYLERS ZEITSCHRIFT FUR PHYSIOLOGISCHE CHEMIE 236: 1 (1935).
2. BONNER, J, BOT GAZ 106: 185 (1944).
3. COPISAROW, M, CHEMISTRY & INDUSTRY 13: 283 (1935).
4. COPISAROW, M, JOURNAL OF POMOLOGY AND HORTICULTURAL SCIENCE 14: 9 (1936).
5. ENGLISH, J, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 61: 3434 (1939).