Here are some topics to look for in catalogs and journals.

Examples of using formal methods
SPIN
the Z language
VDM and/or VDL
The B method
Petri Nets
Semantics of UML
Buchi automata
analysis of requirements
Specification methods
UNITY
SCR = Software Cost Reduction
type systems and errors
proof methods
verifying properties
safety and liveness properties
model-checking
modules and modularity
traces and trace assertion
CSP
ACP
lightweight methods
TCAS
And/Or tables

statecharts


Search for MATH and FORMAL in my  online bibliography.
    http://www.csci.csusb.edu/cgi-bin/dick/lookup

Can also look for names:  Jackson, Parnas, Heitmeyer, Lamport, Broy,
	Rushby, Woodcock, Mili, Luqi, Gries, Parnas, Hinchey, Leveson,
	Harel, Bowen, ..., Botting:-)