There are several sources that discuss Post Traumatic Stress Syndrome in Vietnam vets. The end all and be all of information on psychological disorders is called the DSM IV. That would stand for the Diagnostic and Statistical Manuel, 4th edition. Coincedently, the fourth edition was the first to offer psychologists information on Post traumatic stress... written shortly after the close of the Vietnam war. There are usually copies in any public library as well as online. Also, the Physicians Desk Reference discusses this syndrome. This is a sort of encyclopedia for medical professionals. Where I would also recommend would be discussion groups online for actual war veterens. You would be likely to find actual first hand accounts from people who have had to deal with the disorder.