McGraw-Hill, .
Encyclopedia of Science and Technology Vol-1 / - Reprinted 1971 / - New York : McGraw-Hill Book Company. - p.774 :
07-079798-6
AK73,N60 / L1.1
Encyclopedia of Science and Technology Vol-1 / - Reprinted 1971 / - New York : McGraw-Hill Book Company. - p.774 :
07-079798-6
AK73,N60 / L1.1