00577naa#a2200169#i#450# EN\RIOR\bibl\42576 20240504190919.6 2409-6024 20210414b2021####ek#y0engy0150####ca RU PHILATELISTIC MATERIALS AS AN ADDITIONAL SOURCE FOR STUDYING (RESEARCH) ECONOMIES OF THE STATE Journal article Moscow Publishing Center RIOR 2021 4 с. Journal article local Экономика. Экономические науки. 33 Semin Aleksandr Nikolaevich riorpub.com