Ключевые слова: aged, alexander, ancient, antique, biology, canceled, collection, communication, correspondence, embryologist, evolutionary, historic, history, hobby, kovalevsky, letter, mail, male, man, medicine, message, national, old, paper, perforated, person, philatelic, philately, portrait, post, postage, postal, postmark, professor, retro, russia, russian, science, scientific, seal, soviet, stamp, university, used, ussr, vintage, zoologist,