Frey, P. R. (1965). Chemistry problems and how to solve them. New York: Barnes and Noble.
Παραπομπή Chicago StyleFrey, Paul R. Chemistry Problems and How to Solve Them. New York: Barnes and Noble, 1965.
Παραπομπή MLAFrey, Paul R. Chemistry Problems and How to Solve Them. New York: Barnes and Noble, 1965.
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