6Sims J T,Sharpley A N.Phosphorus:Hammond L L,Van S J Kauwen bergh.Phosphorus as a Natural Resource.Madison,Wisconsin,USA:American Society of Agronomy Inc,Crop Science Society of America Inc,Soil Science Society of America Inc,2005,3 -23.
7Peng F F,Gu Z.Processing Florida dolomitic phosphate pebble in a double reverse fine flotation process[J].Minerals and Metallurgical Processing,2005,22(1):23 -30.
8U. S. Geological Survey. Mineral Commodity Summaries. ht tp://minerals, usgs. gov. 2003.