Glynn Winskel
The Formal Semantics of Programming Languages -- An Introduction, Foundations of Computing Series, MIT Press, Cambridge, MA, 1994.
David A. Schmidt
Denotational Semantics -- A Methodology for Language Development, Allyn and Bacon, Boston, MA, 1986.
PDF sources

David A. Schmidt
The Structure of Typed Programming Languages, Foundations of Computing Series, MIT Press, Cambridge, MA, 1994.

Hanne Riis Nielson and Flemming Nielson
Semantics with Applications - A Formal Introduction, John Wiley & Sons, 1992.
PDF Sources.