Hernández-Medina, Ernesto, and John W. Shive. “Calcium-Boron Relationships in the Nutrition of Corn and the Distribution of These Elements in the Plants”. The Journal of Agriculture of the University of Puerto Rico, vol. 30, no. 4, Oct. 1946, pp. 251-9, doi:10.46429/jaupr.v30i4.12864.