Siddi, Marco (2016). "German foreign policy towards Russia in the aftermath of the Ukraine crisis: A new Ostpolitik?". Europe-Asia Studies. 68 (4): 665–677. doi:10.1080/09668136.2016.1173879. S2CID156187733.
Siddi, Marco (2016). "German foreign policy towards Russia in the aftermath of the Ukraine crisis: A new Ostpolitik?". Europe-Asia Studies. 68 (4): 665–677. doi:10.1080/09668136.2016.1173879. S2CID156187733.