Molnibalage make a real good booklet about the S-300 family: http://www.mediafire.com/file/6vau4j64uwx4sm7/S-300_family.pdf This is the translation of the long Hungarian book what Molnibalage made in cooperation with other guys for ex. with Hpaps, he is well known for the SamSim. This is the whole, in Hungarian: http://www.mediafire.com/file/f5i2wh4wk09ne4p/HT_összefoglaló_2017-nyomtatobarat.pdf The author translated the S-300/400 part because this SAM is very popular and there are many misconceptions about it. Because the chapter is just a part of a big book are some parts in the document which refer to content of the book in other chapters. Slowly I plan to translate the whole book but it could take years to finish the whole book. Have a good reading!