21
Published 2006
OECD Publishing

22
Published 2006
OECD Publishing

23
Published 2002
OECD Publishing

24
Published 2007
OECD Publishing

25
Published 2006
OECD Publishing

26
Published 2006
OECD Publishing

27
Published 2007
Centre for Science Research and Statistics of the Ministry of Education and Science

28
by Schmidt, Chris
Published 1988
Documentary Educational Resources (DER)

29
by Niglas, Liivo
Published 2003
Documentary Educational Resources (DER)

30
by Devisheva, Evelina
Published 2000
Documentary Educational Resources

31
by Andriessen, Louis
Published 1982
Donemus

32
by Devisheva, Evelina
Published 2000
Documentary Educational Resources (DER)

33
by Bernstein, Anya
Published 2006
Documentary Educational Resources

36
by Orshanskij, Lev Grigorʹevich
Published 1923
Gos. izd-vo

37
Published 1938
Profizdat

38
Published 1924
Vysshij voennyj redakcionnyj sovet

39
by Kornilʹeva-Radina, Marija Alekseevna
Published 1925
Izd-vo Narkomzdrava

40
by Krivolapov, Dmitrij Vasilʹevich
Published 1928
Molodaja gvardija