What are some russian war movies and where can i buy them online?

I've agreed to help my grandfather buy some DVD's online, russian war moves to be specific. But i am having trouble finding any as i can't read russian and do not know of any russian movies either. Can anyone help me? What are some good russian war movies and where can i find these? Thanks a lot!|||A couple I can think of off the top of my head are Ivan's Childhood and The Cranes Are Flying, both take place during World War II and are very well known. Alexander Nevsky is another classic one to check out. All are on DVD in the States via Criterion Collection