Hurtak, J. J. The book of knowledge : : the keys of Enoch : a teaching given on seven levels in preparation for the brotherhood of light, to be delivered for the quickening of the "People of Light" / [electronic resource] / J.J. Hurtak.. — Los Gatos, Calif. : : Academy for Future Science,, c1977.. — xvii, 612 p. : : ill. ; 24 cm.