Costa, Newton de Lucena, et al. “Influence of Vesicular-Arbuscular Mycorrhizal Fungi Sources and Levels of Phosphorus on the Growth of Oat Forage”. Pesquisa Agropecuaria Brasileira, vol. 24, no. 8, Apr. 2014, pp. 979-86, doi:10.1590/S1678-3921.pab1989.v24.18386.