Iowa State University. Cooperative Extension Service, Iowa Farm Business Association, & United States. Department of Agriculture. (1934). Iowa farm outlook. Cooperative Extension Service, Iowa State University of Science and Technology.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Iowa State University. Cooperative Extension Service, Iowa Farm Business Association, و United States. Department of Agriculture. Iowa Farm Outlook. Ames (Iowa): Cooperative Extension Service, Iowa State University of Science and Technology, 1934.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Iowa State University. Cooperative Extension Service, et al. Iowa Farm Outlook. Cooperative Extension Service, Iowa State University of Science and Technology, 1934.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.