APA Style conforms to The Bluebook: a uniform system of citation (18th ed., 2005) for legal references, including court decisions, statutes and other legislative materials, e.g.
Thomson v. Saskatoon School Division No. 13 (1996), 144 Sask. R. 11 (Can. Sask. C.A.)
Education Act, 1995, S.S., c. E-0.2 (Can. Sask.)
See the Publication manual (6th ed., pp. 216-224) for additional examples.