Spar, M. A., & Martin, J. H. (1983). Housing units authorized in Virginia's planning districts, counties, and cities: 1st and 2nd quarters, 1982. University of Virginia, Colgate Darden School of Business Administration, Tayloe Murphy Institute.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Spar, Michael A., و Julia H. Martin. Housing Units Authorized in Virginia's Planning Districts, Counties, and Cities: 1st and 2nd Quarters, 1982. Charlottesville, Va.: University of Virginia, Colgate Darden School of Business Administration, Tayloe Murphy Institute, 1983.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Spar, Michael A., و Julia H. Martin. Housing Units Authorized in Virginia's Planning Districts, Counties, and Cities: 1st and 2nd Quarters, 1982. University of Virginia, Colgate Darden School of Business Administration, Tayloe Murphy Institute, 1983.