1. Rohm Haas Amberlite/Duolite Ion Exchange Resins Engineering Manual , Introduction, pp. 24-25, no declared publishing date
2. Abandoned Mine Reclamation Clearing House Treatment Options, at http://www.amrclearinghouse.org, pp. 18-21
3. R. Kunin Amber-Hi-Lites , Spring, 1963
4. Information is also available at the Dow Answer Center, dowmail1@mailwc.custhelp.com
5. S.N. Zaharna Desalting and Purifying Water by Continuous Ion Exchange, US Patent 3607739, assigned to Gulf Degremont, Inc., September 21, 1971