I'm a novice Real Estate Investor (own 4 houses) trying to grow &

[Brent Hayden]

learn. 

I listen to the podcasts from BiggerPockets every day on my commute to/from work.  I want to expand my knowledge and am looking for a good book.  Any suggestions - if you could read one book on real estate investing, where would you recommend I start?  

NOTE:  My goals are as follows:  6 houses by the end of 2017 (using my own capital).  10 Houses by the end of 2018 (mostly leveraging creative financing and minimizing my own capital investment as I will be mostly leveraged at this end of 2017). 

Thanks in Advance for the recommendations!