^The International Bureau For The Standardisation of Man-Made Fibres (BISFA), Terminology of man-made fibres(PDF): 49, 2009 [2013-08-04], (原始内容(PDF)存档于2014-04-11)
^Himmelfarb, David. The Technology of Cordage Fibres and Rope. London: Leonard Hill. 1957: 116.
外部链接
ISO 2:1973(页面存档备份,存于互联网档案馆) Textiles — Designation of the direction of twist in yarns and related products