Martin, F.W. and Hepperly, P. 1987. Sources of resistance to early blight, Alternaria solani, and transfer to tomato, Lycopersicon esculentum. The Journal of Agriculture of the University of Puerto Rico. 71, 1 (Jan. 1987), 85–95. DOI:https://doi.org/10.46429/jaupr.v71i1.6927.