§52.1921. Classification of regions.
40 C.F.R. § 52.1921
The Oklahoma plan was evaluated on the basis of the following classifications:
Notes, amendments, and revision history
Amendments
[37 FR 10887, May 31, 1972, as amended at 45 FR 9741, Feb. 13, 1980]
Authority
Authority: 42 U.S.C. 7401 et seq.
Amendments
[40 FR 5521, Feb. 6, 1975]
Amendments
[37 FR 10887, May 31, 1972, as amended at 45 FR 9741, Feb. 13, 1980]