Heightchew, R. E. (1981). On the evolution of urban transportation planning theory and technique in the United States. University of Maryland.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Heightchew, Robert Earl. On the Evolution of Urban Transportation Planning Theory and Technique in the United States. College Park: University of Maryland, 1981.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Heightchew, Robert Earl. On the Evolution of Urban Transportation Planning Theory and Technique in the United States. University of Maryland, 1981.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.