Clop-Gallart, M.M., and F. Juárez-Rubio. “Short Communication. Persistence of Point Crop Yield Subjective Estimates”. Spanish Journal of Agricultural Research 4, no. 3 (September 1, 2006): 202-206. Accessed May 4, 2025. https://sjar.revistas.csic.es/index.php/sjar/article/view/201.