• Division of signsPeirce, Charles S.; Pietarinen, Ahti-VeikkoSign systems studies = Töid märgisüsteemide alalt = Труды по знаковым системам2015 / p. 651-662 : ill https://doi.org/10.12697/SSS.2015.43.4.16 https://www.scopus.com/sourceid/17700155437 https://www.scopus.com/record/display.uri?eid=2-s2.0-84994009787&origin=inward&txGid=9b4034f686b07f479a8b02afb119725a https://www.webofscience.com/wos/woscc/full-record/WOS:000369351800016