Rojas Tapias, Daniel, Mabel Ortiz-Vera, Diego Rivera, Joseph Kloepper, and Ruth Bonilla. 2013. “Evaluation of Three Methods for Preservation of Azotobacter Chroococcum and Azotobacter Vinelandii”. Universitas Scientiarum 18 (2):129-39. https://doi.org/10.11144/Javeriana.SC18-2.etmp.