Matheus, R., and D. Kantur. “Application of Biourin and Mycorrhizal Fertilizers on the Dynamics of Available P, P Uptake, and Shallot (Allium Ascalonicum L.) Yield in Vertisols”. Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering), vol. 12, no. 2, June 2023, pp. 458-69, doi:10.23960/jtep-l.v12i2.458-469.