TODO

sources parameters

GND: Q36578; P227 examples:

ULAN: Q2494649; P245; URL pattern: implemented!!! here I've also already found reference dupes! :/

RKDartists: Q17299517; P650; URL pattern: implemented!!! quite a few reference dupes examples (also use https://www.wikidata.org/wiki/Special:LinkSearch/https://rkd.nl/):