One of the main reasons I am using Spotify is because I can have most of Donna Summer's catalogue anytime I like BUT Spotify has not make any effort on completing what's missing in her catalogue, songs like: down deep inside, melody of love, je t'aime, anyway at all, carry on that were even singles and there are nowhere in here. Please, try to complete the catalogue with recent compilations like The Ultimate Donna Summer and the reissue of her 80's albums.
Spotify wants all the world's music, and they're working hard on making this happen for you. However sometimes agreements can’t be reached with the artist or label or a change may happen in music ownership.
Spotify adds thousands of albums and artists are added every day. If you can’t find an artist you’re looking for, they may appear (or reappear) soon. In the meantime, feel free to contact the artist or their label to ask when they plan to be on Spotify. https://support.spotify.com/article/Content-missing/