So on the page https://imslp.org/wiki/List_of_works_by ... od%C3%A1ly the list is cataloged by 'K' number, claiming to be based on the book "Zoltán Kodály: A Guide to Research".
Well, currently being in possession of said book and you can see for yourself in Google priview: https://www.google.com/books/edition/Zo ... frontcover ), the catalog is actually completely different, being arranged by genre and not chronological.
So where does this list on IMSLP /actually/ come from?