Not a whitepaper, but: http://www.amazon.com/Microsoft-Server-Internals-Developer-Reference/dp/0735658560/ref=sr_1_1?s=books&ie=UTF8&qid=1435683605&sr=1-1&keywords=sql+server+internals
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability