Donbas region to hold referendum on joining Russia: Moscow-backed separatists

Russia makes moves to annex separatist regions in Ukraine : NPR

Peace in Ukraine (II): A New Approach to Disengagement

Putin illegally annexes territories in Ukraine, in spite of global opposition : NPR

EXPLAINER: What's behind referendums in occupied Ukraine?

Why are parts of Ukraine holding referendums on joining Russia? Here's what you need to know

Four Ukrainian regions controlled by Russian-backed separatists request referendum to join Russia - ABC News

Russia's Moves on Referendums Have Echoes of Putin's Actions in Crimea in 2014 - The New York Times

Rebels without a Cause: Russia's Proxies in Eastern Ukraine

Leader of east Ukraine separatist region says it may hold vote on joining Russia