Zanatta, A.C.A. and Mundstock, C.M. 1991. Effect of phosphorus and aluminum levels on spike structures of wheat. Pesquisa Agropecuaria Brasileira. 26, 9 (Sep. 1991), 1351–1363. DOI:https://doi.org/10.1590/S1678-3921.pab1991.v26.3475.