Check the state against the reporter

Warning²Federal courts, Illinois courts21st and 22nd editions

A regional reporter prints the decisions of its own states only, so “(Cal. 1930)” after an N.E. citation names a state that reporter does not report.¹

1. 1R. 10.4(b) State courts. Tables: R. 23.7.2(b) Other courts; T10.1 U.S. States, Cities, and Territories.
2. 2A warning: the form is usually wrong under the rule in note 1, and context can justify it.