"With the exception of chapter 9, which is entirely new, the material ... has been drawn in large part from 'Kreking v zhidkoi faze (Khimiya i tekhnologiya)' by Professor A. N. Sachanen i M. D. Tilicheyev, Neftyanoe Izdatelstvo, 1928, which has been thoroughly revised and in many instances completely rewritten."--Authors' pref.