Stumped by jquery.find() method for parsing JSON from Wiktionary API

I'm using this code as a starting point to parse JSON returned via the Wiktionary API. I want to customize this code to extract just the IPA pronunciation info for any word. I'd hoped to write it all myself but was getting nowhere so I started messing around with the code linked above. I understand almost all of it, but where I hit a wall is with this:

$("#wikiInfo").find('a:not(.references a):not(.extiw):not([href^="#"])').attr('href',
function() {
    return baseURL + $(this).attr("href");
    }
);

I understand the .find() method, but the chain of :not() selectors and what appears to be a compound selector a:not(.references a) filtering all links with class 'references' inside links? Huh?

Do the successive :not() selectors apply an additional filter? I'm totally lost. Can someone please explain what's going on in the above pasted code?