I was just wondering if anybody knows of any good books or articles that study rings (and algebras) without (or not necessarily with) identity. I have gone through Thomas Hungerford's $Algebra$ textbook (and loved it), but every book I have read afterwards on noncommutative algebra (Farb and Dennis' $Noncommutative$ $Algebra$ and T. Y. Lam's $A$ $First$ $Course$ $in$ $Noncommutative$ $Rings$) have assumed that all rings are unitary. Could anyone give me a good reference please? Thank you all in advance!
Jacobson's Structure of rings develops a bit of ring theory without assuming identity. Also Gardner and Wiegandt's book Radical Theory of Rings does not assume identities.
Any book on $C^*$ algebras would also have to deal with rings missing identity.