Name the methods for extracting phosphorous

Phosphorus/phosphate - Phosphorous is estimated as phosphate. Some methods for extracting phosphorous are as follows:  

Dyer method :  1% Citric acid used for extracting available soil phosphate . 

Bray and Kurtz method  :  Phosphate is extracted with a solution of 0.03M NH4F  in 0.025M HCl and 0.5M NaHCO3 and solution adjusted to pH 8.5 . 

Olsen's method    :  Phosphate is extracted with 0.5M NaHCO3 adjusted to pH 8.5 with 10% caustic soda. 

The extracted phosphate develops colour when treated with ammonium molybdate and stannous chloride. The colour intensity is measured with the help of a colorimeter.