Cannabis Alchemy: Art of Modern Hashmaking By D. Gold
1993 | 109 Pages | ISBN: 0914171402 | PDF | 7 MB
This book tells you how to concentrate active ingredients from Cannabis, and how to modify them to improve their potency.
The instructions given are distilled from technical writings, which are cited. These technical journals may be hard to come by, since the articles are often old (but valid).