David M. Glantz wrote several good books on the Eastern Front. Glantz had access to the Russian archives and made extensive use of Russian files for his studies. I especially was impressed by his "When Titans Clashed, How the Red Army stopped Hitler". But a few of his long list of publications are:
See also Johanthan M. House. Together with David Glantz, House co-authored several books on the military history of the Eastern Front.
Old but good... John Erickson's road to Stalingrad and Road to Berlin. John met many of the Soviet commanders in the 1960s. John Erickson (historian) - Wikipedia
From the perspective of 'a' Soviet: Evgeni Bessonov - Tank Rider. Well-written/translated & convincing memoir of one infantryman's pretty intense war. More about the day-to-day survival than grand strategy, I (and others I've forced it on) thoroughly enjoyed it.
A Writer at War: Vasily Grossman with the Red Army (Vasily Grossman) Lady Death: The Memoirs of Stalin's Sniper (Lyudmila Pavlichenko)
What's sad is that we'll likely never know the full truth of the Soviet perspective because of Soviet censorship during and after the war. Hearing Zhukov's uncensored views would be fascinating.
Grossman's embedded account of being in the front line with the Red Army to Berlin is worth while reading. He did suffer some disadvantages as he recalls from being of the Jewish faith.
Yulia Zhukova's Girl With a Sniper Rifle. Good insights on the Cental Women's Sniping School and war from a woman's perspective. Roza Shanina's diary has been translated into english. Born Under a Lucky Star. Red Road From Stalingrad.
Not a book but an institution whose website I cited heavily in my book. The organization interviewed many Red Army veterans. They transcribed the interviews so people like me can understand and use them: Blavatnik Archive Foundation I read the foreword to one book and learned that many of the current books by veterans had one man, Artem Drabkin's involvement. He went on to interview many veterans and posted them (along with english translation). His works were also cited by me. Hit the "EN" button on the top so you can read it: Воспоминания ветеранов Великой Отечественной Войны Between both sites, you can spend hours of reading. Have fun and good luck in your own research.