Agren, L. (1990). .Swedish direct investment in the U.S. IIB, Institute of International Business, Stockholm School of Economics.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Agren, Lars. .Swedish Direct Investment in the U.S. Stockholm, Sweden: IIB, Institute of International Business, Stockholm School of Economics, 1990.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Agren, Lars. .Swedish Direct Investment in the U.S. IIB, Institute of International Business, Stockholm School of Economics, 1990.