McGraw-Hill, .
Encyclopedia of Science and Technology Vol-9 / - Reprinted 1971 / - New York : McGraw-Hill Book Company. - p.707 :
07-079798-6
AK73,N60 / L1.9
Encyclopedia of Science and Technology Vol-9 / - Reprinted 1971 / - New York : McGraw-Hill Book Company. - p.707 :
07-079798-6
AK73,N60 / L1.9