Paul Otlet was a Belgian, *1868, died 1944, who perfected the Dewey Classification system as "the Universal Decimal Classification", in his lifetime alone totalling 17 million index cards of human knowledge.
2016
2023
2014
2007
2021
2022
1971
2011
1969
—
2013
2002
1990
1974
2004
1994
2009