The problem is that some of these world bosses spawn at random time durations after they were last killed - it's not really possible to post that information here at the website.

The only way to do it would be to add an ingame announcement that they spawned like we have for the bosses that spawn at specific times, like Nereus, Bears, Okeanos etc. etc. but it could possibly make it more difficult to get the bosses you need as everyone would know they spawned and go to defeat them.

thats make sense , but since we have low population it still worth to do