Here is a short list of some of the best books on earning passive income. I did a simple search on Amazon.com.
1. Passive Income in 90 Days by Willam U. Pena. MBA $7.99 paperback.
2. Passive Income: 40 Ideas to Launch Your Online Business including blogging,ecommerce, dropshipping…by David J Green.
3. Passive Income: 25 Proven Business Models To Make Money Online From Home. by Mark Atwood.
4. Passive Income : 30 Strategies and Ideas to Start An Online Business and Acquiring Financial Freedom by Richard Gadson.
5. How to Make $100,000 Per Year in Passive Income and Travel the World by Chase Andrews.
6. AFFILIATE SYSTEM: 7 Steps to Build an Affiliate System in Just One Month and Earn $100 Daily From It by Lsa Casey.
7. How to Make Money Online: Learn How to Make Money from Home with my step-by-step plan to build a $5,000 a month passive income by Mike Omar.
8. Passive Income: 14 Ways to Make $5,000 a Month in Passive Income by Chad Tennant.
9. Passive Income: Stop Working-Start Living-Make Money While You Sleep by Ralph Waters.
10. Affiliate Marketing: Lauch a Six Figure Business with Clickbank Products, Affiliate Links, Amazon Affiliate Program and Internet… by Noah Grey
11. Affiliate Marketing: How to Make MoneyOnline and Build Your Own $100,000 Affiliate Marketing Online Business, Passive… by Anthony Parker
12. Affiliate Marketing: 2017 EDITION. Develop An Online Business Empire From Selling Other People’s Products by Adam Wolf.
On this webite I emphasize affilaite marketing as a good way t0 increase your income greatly. It is a realistic and legitimate business. There is a lot to learn so I reccommend reading other books and sources besides my own blog. I wish you happy reading and much success. I will do my best to help you.