(1961). Specialized science information services in the United States: A directory of selected specialized information services in the physical and biological sciences. Washington: National Science Foundation. Office of Science Information Service.
Παραπομπή Chicago StyleSpecialized Science Information Services in the United States: A Directory of Selected Specialized Information Services in the Physical and Biological Sciences. Washington: National Science Foundation. Office of Science Information Service, 1961.
Παραπομπή MLASpecialized Science Information Services in the United States: A Directory of Selected Specialized Information Services in the Physical and Biological Sciences. Washington: National Science Foundation. Office of Science Information Service, 1961.