- Classification Society of North America (CSNA) Welcome to the home page of the Classification Society of North America (CSNA). The CSNA is a nonprofit interdisciplinary organization whose purposes are to promote the scientific study of classification and clustering (including systematic methods of creating classifications from data), and to disseminate scientific and educational information ...www.pitt.edu/~csna
- An article summarizing the UDC.www.oasis-europe.org/docs/en/d0305/node87.html