Wintershall AG <Kassel>. (1999). Hampelman i matrjoschka: Derwjannaja igruschka is Germanii i Rossi ; Wistawka Wintershall AG i OAO Gazprom. Wintershall AG.
Cita Chicago (17th ed.)Wintershall AG <Kassel>. Hampelman I Matrjoschka: Derwjannaja Igruschka Is Germanii I Rossi ; Wistawka Wintershall AG I OAO Gazprom. Kassel: Wintershall AG, 1999.
Cita MLA (8th ed.)Wintershall AG <Kassel>. Hampelman I Matrjoschka: Derwjannaja Igruschka Is Germanii I Rossi ; Wistawka Wintershall AG I OAO Gazprom. Wintershall AG, 1999.
Atenció: Aquestes cites poden no estar 100% correctes.