Neloth quest end? (help with research)

[DON'T SHOOT!!]

I have been keeping myself busy with Neloth questline (the Telvanni wizzard). I have:
- defeated Mirak
- acquired all the black books
- killed his former steward
- gave him a new steward
- went with him to the Dwemer ruins for one of the black books
- gathered ashspawn samples
- had a failed spell casted on me (the one that weakens you in water)
- collected his heart stones like 4 times
- brought him 4 staffs at least

PROBLEM:
He keeps giving me the same 2 quests: heart stones and find him staffs!!

Is this the end of his story? Does he just keep repeating these two quests? You never end up finishing his research with him?

[Docsprock]

https://en.uesp.net/wiki/Dragonborn:Neloth

[DON'T SHOOT!!]

Well acc to the wiki. I never got the Experiment (B) quest. All others I did already.