Não informado. (1968). Government Reports Index. U.S. Department of Commerce, National Technical Information Service.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Government Reports Index. Washington: U.S. Department of Commerce, National Technical Information Service, 1968.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Government Reports Index. U.S. Department of Commerce, National Technical Information Service, 1968.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.