Walker, M. (1963). The Nature of Scientific Thought. Englewood Cliffs, New Jersey: Prentice-Hall.
Dyfyniad Arddull ChicagoWalker, Marshall. The Nature of Scientific Thought. Englewood Cliffs, New Jersey: Prentice-Hall, 1963.
Dyfyniad MLAWalker, Marshall. The Nature of Scientific Thought. Englewood Cliffs, New Jersey: Prentice-Hall, 1963.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.