Signs systematically studied : invitation to Peirce's theoryPietarinen, Ahti-VeikkoSign systems studies = Töid märgisüsteemide alalt = Труды по знаковым системам2015 / p. 372-398 https://doi.org/10.12697/SSS.2015.43.4.01 https://www.ester.ee/record=b4554246*est Journal metrics at Scopus Article at Scopus Article at WOS