This series is broken into two sections. The first deals with technological developments such as helicopters, air power, riverine war technologies. The second deals with the subject of chemical and biological warfare including Agent Orange. This section cover the use of weapons systems during the Vietnam Conflict. The material is primarily secondary in nature with an emphasis on research and development. General subject headings include: use of airpower, helicopters, anti- aircraft technology, target selection for bombing and air strike missions, riverine warfare, electronic barriers, and technical intelligence. Also included in this section is information relating to chemical and biological warfare in Vietnam, specifically the use and effects of toxic agents for defoliation and crop destruction programs such as Agent Orange and the issue of 'yellow rain.' Finally, this section examines the Ho Chi Minh Trail and its use during the war.