Madyev S. A. & Ivanova V. S. Veronika Sergeevna. (2015). First Artificial Earth satellite. 2015.
Cita Chicago (17th ed.)Madyev S. A. i Ivanova V. S. Veronika Sergeevna. First Artificial Earth Satellite. 2015, 2015.
Cita MLA (9th ed.)Madyev S. A. i Ivanova V. S. Veronika Sergeevna. First Artificial Earth Satellite. 2015, 2015.
Atenció: Aquestes cites poden no estar 100% correctes.