Some is from what I heard and was taught in priesthood meetings; Sunday school lessons, and ward and stake talks. Some of the other is from first hand experience as a member for a little over three years. Additionally, some of what used to be considered credible literature from mormon authors has been reevaluated and now deemed to be unreliable. One of the main go to books for information on mormonism while I was a member was written by one of their apostles, Bruce R. McConkie, and was called Mormon Doctrine. That book has fallen out of favor due to changing views or their current apologetic. Any prior general authority, other than Joseph Smith Jr. can, and will be thrown under the bus if they have ever written or taught anything that could prove to be embarrassing today, including any talks given at general conference or published in official church publications. IOW, I was in the belly of the beast. Cheers.