The principles of scientific research /
Freedman, Paul.
The principles of scientific research / by Paul Freedman. - Oxford : Pergamon Press, c1960. - xvii, 228 p. : ill.
Research.
Scientific research.
The principles of scientific research / by Paul Freedman. - Oxford : Pergamon Press, c1960. - xvii, 228 p. : ill.
Research.
Scientific research.