C. L. Bergmark BERGMARK, C. L., JACKSON, W. A., VOLK, R. J., & BLUM, U. (1992). DIFFERENTIAL INHIBITION BY FERULIC ACID OF NITRATE AND AMMONIUM UPTAKE IN ZEA-MAYS L. PLANT PHYSIOLOGY, 98(2), 639–645. https://doi.org/10.1104/pp.98.2.639