Chobanov, G., & Plöhn, J. (2013). Crisis and sustainability: Responses from different positions : 14th Annual Conference of the Faculty of Economics and Business Administration Sofia, 7-8 October 2011. Peter Lang AG.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Chobanov, George, و Jürgen Plöhn. Crisis and Sustainability: Responses from Different Positions : 14th Annual Conference of the Faculty of Economics and Business Administration Sofia, 7-8 October 2011. Frankfurt am Main, [Germany]: Peter Lang AG, 2013.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Chobanov, George, و Jürgen Plöhn. Crisis and Sustainability: Responses from Different Positions : 14th Annual Conference of the Faculty of Economics and Business Administration Sofia, 7-8 October 2011. Peter Lang AG, 2013.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.