Russian language 54 mathematics 44 physics 38 physical chemistry 31 nuclear physics 30 organic chemistry 24 mineralogy 18 more ... German language 18 English language 17 chemistry 17 inorganic chemistry 14 engineering 14 history 13 Czech language 13 French language 12 metals 12 functions 11 architecture 10 astronomy 10 Spanish language 10 bibliography 9 general chemistry 9 electrotechnics 8 Italian language 8 natural sciences 8 dictionaries 8 towns 7 polymers 7 biochemistry 6 chemical technology 6 less ...