1. Evolution of Molecular graphics;Wipke,1987
2. Distributed by Tripos Associates Inc., 1699 South Hanley Road Suite 303, St. Louis MO 63144, USA.
3. The Protein Data Bank: A Computer-based Archival File for Macromolecular Structures;Berstein;J. Mol. Biol.,1977
4. Cambridge Scientific Computing Inc., P.O. Box 2123, Cambridge, MA 02238.
5. ATOMS - A three-D opaque molecule system for color pictures of space-filling or ball-and-stick models;Knowlton;Computers & Chemistry,1977