The following books are purely for educational purposes only if you live in the UK.
However, you may still wish to absorb the knowledge in these books, just in case they legalise marijuana in the UK in the future. If you live in a sensible country such as Holland, Belgium, Spain, Portugal, Switzerland or even certain US states, where it may be legal to grow herbal highs and cannabis plants then the information in these books may prove more useful. You may of course read the book in the UK and then move to Holland to grow your own cannabis.
Please do not use any of the information in these books for the cultivation of cannabis in the UK without a license from the Home Office (for this you need to be a big pharmaceutical company that donates large amounts of money to the Labour Party such as GW Pharmaceuticals).