1. Independent; 838 Grooms Rd. Rexford NY 12148 USA
2. Institute of Chemical Research of Catalonia (ICIQ); Barcelona Institute of Science and Technology; Avda. Països Catalans, 16, 43007 Tarragona Spain
3. No longer affiliated with ICIQ
4. E. I. DuPont de Nemours & Co., Inc., Experimental Station; 200 Powder Mill Rd. Wilmington DE 19803 USA