Books worthy of reference

I have nothing against the novel. I have read many in my lifetime.  However, as reference guides, these books are worth checking back with when questions arise.

• Science Matters - when you're not sure how the basic science works, check this book.
  
• How to Win Friends and Influence People - there's a reason why this book is still in print after almost a century!
• Aging Well - 5 simple things to ensure a positive old age