The Restore Life effect of Master Transmuter on PHB119 reads:
You cast the raise dead spell on a creature you touch with the transmuter's stone, without expending a spell slot or needing to have the spell in your spellbook.
Perhaps I'm reading into it too much, but does this imply that it is otherwise possible (independently of Master Transmuter) to add raise dead to the spellbook? I know that it is not listed as a Wizard spell, and even a Necromancer seems unable to achieve this pinnacle of necromancy.
Can it be done, under any circumstances? Are there any tricks or loopholes?