Tract books were supplemented with additional records on little blue cards known as micro fiche sorted by time and name. 

We BRRRR 8-10 per year and the flips supplement the money left in the BRRRRs. 

Housing Discriminationhttps://ipropertymanagement.com/laws/landlord-tenant-rights"Also, many states (and even some cities) supplement these federal regulations with their own set of protected classes.

I've done this.I had ~$50k in savings but supplemented it with a $130k HELOC. 

Basically I have a supplemental permit that says SB9 2-unit development, the old house is unit 1 and the ADU is now unit 2.

I know that @J Scott wrote a pretty good book on the process though, (just finished it this weekend), and I would recommend starting with that.If you purchase the book(s) from BiggerPockets (as opposed to Amazon), they come with a bunch of digital files to supplement the material. 

I would need to probably include farm profits in my calculations because the hope would be to eventually farm full time, but also supplement current income till I can move to farming full time. 

But more properties will be needed than buying in cash.Appreciation/equity paydown: Cash flow from rents will be supplemented by property value gains and tenants paying down your mortgage.As a rough estimate, assuming you can buy properties for $150k that rent for $1,500/month with 50% expense ratios, each property may cash flow around $750/month or $9k/year.

I work in Construction Project Management and have found that way more people than I think have found an avenue into RE that has been supplemental income and even a hobby for them depending upon which route they took.

However, if you want 3-5 fully paid off houses in 20-30 years to supplement your retirement, then putting a little more down makes sense so you're not having to fund the property out of your personal cash flow.