You can now find cheap roulette books on Kindle Amazon. Some are trash others are very good indeed.
nolinks://nolinks.amazon.com/Kindle-eBooks/b?ie=UTF8&node=154606011#/ref=nb_sb_noss?url=node%3D154606011&field-keywords=roulette&rh=n%3A133140011%2Cn%3A%21133141011%2Cn%3A154606011%2Ck%3Aroulette (nolinks://nolinks.amazon.com/Kindle-eBooks/b?ie=UTF8&node=154606011#/ref=nb_sb_noss?url=node%3D154606011&field-keywords=roulette&rh=n%3A133140011%2Cn%3A%21133141011%2Cn%3A154606011%2Ck%3Aroulette)