Ruy, V. D. M., Brasil Sobrinho, M., & Malavolta, E. (1987). Contribution to the study of available boron soils of the state of S. Paulo, Brazil: I . Growth and mineral composition of sunflower (Helianthus annus Mill.) . Anais Da Escola Superior De Agricultura Luiz De Queiroz, 44(1), 695-739. https://doi.org/10.1590/S0071-12761987000100037