1. Fujita T (1989) Invention and development of polyolefin-coated urea. Ph D thesis, Faculty of Agriculture, Tohoku University. Sendai, Japan
2. Fujita T, Takahashi C, Ohshima M, Ushioda T and Shimizu H (1977) Method of producing coated fertilizers. United States Patent 4,019,890
3. Fujita T, Takahashi C, Yoshida S and Shimizu H (1983) Coated granular fertilizer capable of controlling the effects of temperature upon dissolution-out rate. United States Patent 4,369,055
4. Fujita T, Yamashita Y, Yoshida S and Yamahira K (1989) Granular fertilizers with a degradative coating. United States Patent 4,881,963.
5. Gandeza AT, Shoji S and Yamada I (1991) Simulation of crop response to polyolefin-coated urea. I. Field dissolution. Soil Sci Soc Am J 55: 1462?1467