Dusk Maiden of Amnesia (Tasogare Otome x Amnesia) guide:

Best version for the manga:
https://nyaa.si/view/2025333
For anime this is the best version, it's the only release that has the Japanese commentary tracks + subtitles from the Blu-ray.
https://nyaa.si/view/1981798
OVA:
https://nyaa.si/view/1981799
But no extras, get the extras from this release except the OST folder:
https://nyaa.si/view/1976391
The best OST collection is this release:
https://nyaa.si/view/1680790
The Drama CD that released 2 years before the anime is in the mega link, plus Takane Shijou Master Artist 4 album, they're not available on at least any public tracker. I bought those CD from Mercari Japan and ripped them myself:
https://mega.nz/folder/K3pGxRhQ#r6KPutuXi8ji-1xC5xcxQw
Maybe (the author)'s official hentai works:
https://e-hentai.org/tag/artist:maybe
Yumi Hara (Yuuko Kanoe's VA) album collection:
https://nyaa.si/view/1701148
Yumi Hara's IM@S Takane Shijou albums can be found in other IDOLM@STER album collections on nyaa