Russian language 54 mathematics 46 physics 39 physical chemistry 31 nuclear physics 30 organic chemistry 24 mineralogy 18 more ... German language 18 English language 17 chemistry 17 engineering 15 inorganic chemistry 14 metals 14 history 13 Czech language 13 French language 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 polymers 7 acoustics 6 biochemistry 6 chemical technology 6 less ...