Ritschel, P. S., & Huamán, Z. (2002). Morphological variability of the sweetpotato germplasm collection of the Embrapa-Centro Nacional de Pesquisa de Hortaliças. Pesquisa Agropecuaria Brasileira, 37(4), 485–492. https://doi.org/10.1590/S1678-3921.pab2002.v37.6365