000
002770000a22001210004500
245
_a
The principles of scientific research
100
_a
Freedman, Paul
260
_a
London
_b
Macdonald
_c
1949
300
_a
222 p.
080
_a
5.001.5
_b
F7
041
_a
EN
942
_c
BK
999
_c
52996
_d
52996