The Nitrogen Fixing Tree Association is a good source of information. The mailing address is: NFTA P.O. 680 Waimanalo, Hawaii 96795 or 1010 Holomua Road Paia, Hawaii 96779-9744 These are addresses from 1991 and they may have moved. But any major Univesity with a Forestry Library should have their publications in their library.