"Structural Characteristics of Paper" (PDF). Georgia Tech. Retrieved 2015-08-15. http://ipst.gatech.edu/faculty/ragauskas_art/technical_reviews/paper%20characteristics.pdf ↩
"ISO 534:2011(en) Paper and board — Determination of thickness, density and specific volume". https://www.iso.org/obp/ui/#iso:std:53060:en ↩