1. AHMED, I., Subbiah, B. V. and Dakshinamurti, C. Studies in the migration of sulphate ion through the soil using 35S as a tracer. Pl. Fd. Tokyo (1971).
2. Shallow depth placement of (NH4)2SO4 in submerged rice soils as related to gaseous losses of fertilizer nitrogen and fertilizer efficiency;ALEKSIC;Plant Soil,1968
3. A diffusion and mass flow concept of soil nutrient availability;BARBER;Soil Sci.,1962
4. BARBER, S. A. The role of root interception, mass-flow and diffusion in regulating the uptake of ions by plants from soil. In: Limiting Steps in Ion Uptake by Plants from Soil. IAEA Tech. Rept. No. 65, 39–45, IAEA, Vienna (1966).
5. BARBER, S. A., Walker, J. M. and Vasey, E. H. Principles of ion movement through soil to the plant root. Int. Soil Conf. N.Z., 121(1962).