Reddit reviews Russia's Warplanes. Volume 1: Russia-made Military Aircraft and Helicopters Today: Volume 1

You actually don't need more than 2-3 books, and the skills in 'reading between the lines' of a few articles. Question is exactly what books, and what articles: problem is that certain 'prominent' authors on Russian military aviation (say Yefim Gordon) are actually copy-pasting from plenty of native sources, and then picking cherries at their own discretion. Result are illusions and legends.

In regards of books, I would recommend Piotr Butowski's recent Russia's Warplanes (there are two volumes) and Russia's Air-Launched Weapons. Combined, they are very useful as 'starting points', even though the latter is lacking precision in regards of specific missile projects.

A regular visit of specialised sections of the ACIG.info forum (requires registration to read) helps 'sort out ambient noises' from 'reality' in regards of all the online reporting. That platform is online since 19 years, and frequented by people who really know what 'research' and 'critical thinking' means.

If you are interested and have some spare money, I’d suggest checking Butowski’s Russia's Warplanes (3 volumes in total), Volume 1 https://www.amazon.com/dp/0985455454/ref=cm_sw_r_cp_api_oNLOAbJTPEHF3

Also note that the fact that Jane’s used to publish some of his articles doesn’t inherently result in a high quality work on this topic from their other writers. Sadly, I’ve seen some similar wild claims about radar and engines coming from them, which is completely unsupported by the insider information about the project, that I’ve seen.

Ironically, the major issue resulting in program falling behind for several years (arguably) is completely ignored by these publications. I guess, insufficient airframe strengthening doesn’t sound as fancy and isn’t that useful when one is trying to construct a fairy tale about technologically inferior competitor product.