Não informado. (1999). Miscellaneous Publications. U.S. Department of Commerce, National Bureau of Standards.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Miscellaneous Publications. Washington: U.S. Department of Commerce, National Bureau of Standards, 1999.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Miscellaneous Publications. U.S. Department of Commerce, National Bureau of Standards, 1999.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.