They also did a historical survey of various such efforts: https://docs.google.com/spreadsheets/d/1f86L7vgHUW9wSLNNSunhjmtxtg6KlCOVpHGKbqUzW-Y/edit#gid=0 https:

They also did a historical survey of various such efforts: https://docs.google.com/spreadsheets/d/1f86L7vgHUW9wSLNNSunhjmtxtg6KlCOVpHGKbqUzW-Y/edit#gid=0 https://docs.google.com/spreadsheets/d/1f86L7vgHUW9wSLNNSunh.... 72 entries.