↑Roskas - may kasirigngon nga "screw tread" ha basahon ni Abuyen, Tomas A.Diksyunaryo Waray-Waray [Visaya] English-Tagalog. Kalayaan Press Mktg. Ent., Inc. Quezon City. Tuig 2000.ISBN 971-08-6050-X. Pakli Ihap 315.
Hallowell, Howard Thomas, Sr (1951),How a Farm Boy Built a Successful Corporation: An Autobiography, Jenkintown, Pennsylvania, USA: Standard Pressed Steel Company,LCCN52001275,OCLC521866.
Ryffel, Henry H. (eds); et al. (1988),Machinery's Handbook (23rd ed.), New York: Industrial Press, ISBN.Unknown parameter|author-separator= ignored (help)CS1 maint: extra text: authors list (link)
