Volume 57 Issue 1 1972 Article Open Space Zoning: Valid Regulation or Invalid Taking Jon A. Kusler View Full Article In This Issue Open Space Zoning: Valid Regulation or Invalid Taking Federal Rule of Civil Procedure 15(c): Relation Back of Amendments The Minnesota Public Employement Labor Relations Act of 1971: Another Public Employment Experiment The Uniform Marriage and Divorce Act--Marital Age Provisions Regulation X and Investor-Lender Margin Violation Disputes