Where have you looked for information?
Have you tried Fantastic Fiction (
https://www.fantasticfiction.com/)? This is my first port of call when I'm trying to sort out the order of books in a series. They usually order the books chronologically as opposed to by publication date.
I also use FictFact (
https://www.fictfact.com/). They often have a link to the author's own website.
Neither's perfect, but I can usually get to the bottom of things by using the two together.