Kettridge, . J. O. (1963). French-English and English-French dictionary of technical terms and phrases used in civil, mechanical, electrical, and mining engineering, and allied sciences and industries, includings geology ... and a method of telegraphic coding, by which any entry in the dictionary can be expressed by a 10-letter cipher word with indicator and check. London: George Routledge & Sons.

Kettridge, J. O. French-English and English-French Dictionary of Technical Terms and Phrases Used in Civil, Mechanical, Electrical, and Mining Engineering, and Allied Sciences and Industries, Includings Geology ... and a Method of Telegraphic Coding, By Which Any Entry in the Dictionary Can Be Expressed By a 10-letter Cipher Word With Indicator and Check. London: George Routledge & Sons, 1963.

Kettridge, J. O. French-English and English-French Dictionary of Technical Terms and Phrases Used in Civil, Mechanical, Electrical, and Mining Engineering, and Allied Sciences and Industries, Includings Geology ... and a Method of Telegraphic Coding, By Which Any Entry in the Dictionary Can Be Expressed By a 10-letter Cipher Word With Indicator and Check. London: George Routledge & Sons, 1963.