Pickering, P. S. U. 1908. Obituary of Robert Warington: born 22 August 1838, died 20 March 1907. Journal of the Chemical Society - Transactions. 93, pp. 2259-2269.
Hall, A. D. and Amos, A. 1906. XXVII - The determination of available plant food in soil by the use of weak acid solvents. Part II. Journal of the Chemical Society - Transactions. 89, pp. 205-222. https://doi.org/10.1039/CT9068900205
Hall, A. D. 1904. XCVI - The mechanical analysis of soils and the composition of the fractions resulting therefrom. Journal of the Chemical Society - Transactions. 85, pp. 950-963. https://doi.org/10.1039/CT9048500950