Não informado. (2000). Technical note. U.S. Department of Commerce, National Bureau of Standards.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Technical Note. Washington: U.S. Department of Commerce, National Bureau of Standards, 2000.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Technical Note. U.S. Department of Commerce, National Bureau of Standards, 2000.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.