While Leroquais' information on provenance has been taken over without alteration, his dating of the sources has been adapted for searching and sorting.
Centuries are indicated with arabic numbers, then the period (if known), for example:
14i = 1301-33, or first half, or first third, or first quarter
14m = 1334-66, or second third, or second or third quarter
14x = 1367-99, or second half, or last third, or last quarter
14xs = 14./15. c.
Precise dates, if known, are given in brackets after the period, for example: