WASET
    Leandro X. Cardoso and  Susana O. Souza and Fernanda C. L. Ferreira and  Orlando C. Ferreira and  Elenilson Barboza and  Carlos E. Alhanati,  Determination of the Specific Activity of Soil and Fertilizers in Sergipe - Brazil.   journal   = {International Journal of Geological and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    August 2011, vol. 56(8). 425 - 430
    [viewed 25 April 2024]. Available from: https://publications.waset.org/pdf/9572.