Soil water retention with vanchenuchten model?

Question

i want to predict water retention curve with vanchunchten model but i dont khow n and m and a in model and i don how i can estabilish them.please guide me .if some one have this article please send to my [e-mail] .i will send my thesis.thanks alot

Answer 1

The first link is the research article, the second link defines 'a',  'n' and 'm'