National Referral Center for Science and Technology (Estados Unidos). (1965). A directory of information resources in the United States: Physical sciences, biological sciences, engineering. National Referral Center for Science and Technology.
Cita Chicago Style (17a ed.)National Referral Center for Science and Technology (Estados Unidos). A Directory of Information Resources in the United States: Physical Sciences, Biological Sciences, Engineering. Washington: National Referral Center for Science and Technology, 1965.
Cita MLA (9a ed.)National Referral Center for Science and Technology (Estados Unidos). A Directory of Information Resources in the United States: Physical Sciences, Biological Sciences, Engineering. National Referral Center for Science and Technology, 1965.
