Add the original citation

Warning²Federal courts, Illinois courts21st and 22nd editions

A microform is cited as related authority — the original document in full, then “microformed on” and the series that filmed it.¹

1. 1R. 18.6(a) Microform collections reproducing preexisting materials; R. 18.5.1 Microform Collections Reproducing Preexisting Materials. Tables: R. 1.6 Related Authority.
2. 2A warning: the form is usually wrong under the rule in note 1, and context can justify it.