Whitney, M., Means, T. H., & United States. Division of Soils. (1897). An electrical method of determining the soluble salt content of soils: With some results of investigations on the effect of water and soluble salts on the electrical resistance of soils. G.P.O..

Whitney, Milton, et al. An Electrical Method of Determining the Soluble Salt Content of Soils: With Some Results of Investigations on the Effect of Water and Soluble Salts on the Electrical Resistance of Soils. G.P.O., 1897.