Donald Lam is a fictional American detective created by Erle Stanley Gardner under his penname A. A. Fair. He is the side-kick of Bertha Cool, a stout widow in her 60s who started their detective agency in 1936.

The series is also known as The Unlikely Duo and consists of the following 29 books:

  • The Bigger They Come
  • Turn on the Heat
  • Gold Comes in Bricks
  • Spill the Jackpot
  • Double or Quits
  • Owls don't Blink
  • Bats Fly at Dusk
  • Cats Prowl at Night
  • Give 'em the Ax
  • Crows can't Count
  • Fools Die on Friday
  • Bedrooms have Windows
  • Top of the Heap
  • Some Woman won't Wait
  • Beware the Curves
  • You can Die Laughing
  • Some Slips don't Show
  • The Count of Nine
  • Pass the Gravey
  • Kept Woman can't Quit
  • Bachelors Get Lonely
  • Shills can't Count Chips
  • Try Anything Once
  • Fish or Cut Bait
  • Up for Grabs
  • Cut Thin to Win
  • Widows Wear Weeds
  • Traps Need Fresh Bait
  • All Grass isn't Green