Cloth covers & liquid spot

Any tips for removing faint liquid stains (not sure what) from cloth covers? There also appears to be reside around the slipcase label, any ideas for that? Photos here: https://imgur.com/a/IITD3p0

Just ordered Absorene and may give it a go.

Well, Absorene did nothing for the liquid spots, though it did get a mark off another book I have so it wasn’t a waste. Still open to ideas... not sure if the marks are just from water or something more.

The residue around the slipcase label is likely glue. I'd leave it be.