Wintershall AG <Kassel>. (1999). Hampelman i matrjoschka: Derwjannaja igruschka is Germanii i Rossi ; Wistawka Wintershall AG i OAO Gazprom. Wintershall AG.
Citazione stile Chigago Style (17a edizione)Wintershall AG <Kassel>. Hampelman I Matrjoschka: Derwjannaja Igruschka Is Germanii I Rossi ; Wistawka Wintershall AG I OAO Gazprom. Kassel: Wintershall AG, 1999.
Citatione MLA (8a ed.)Wintershall AG <Kassel>. Hampelman I Matrjoschka: Derwjannaja Igruschka Is Germanii I Rossi ; Wistawka Wintershall AG I OAO Gazprom. Wintershall AG, 1999.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.