Lüttinger, P., & Wolf, C. (2011). GESIS-Technical Reports. GESIS.
Cita Chicago (17th ed.)Lüttinger, Paul, i Christof Wolf. GESIS-Technical Reports. Mannheim: GESIS, 2011.
Cita MLA (8th ed.)Lüttinger, Paul, i Christof Wolf. GESIS-Technical Reports. GESIS, 2011.
Atenció: Aquestes cites poden no estar 100% correctes.