61 books • 6 series
Work Toward Knowing
Pioneer Auto Show (Discoveries... America S.)
Matchstick Marvels (Discoveries... America S.)
Mark Twain Himself (Discoveries... America S.)
Mississippi (Discoveries... America S.)
Mark Twain's "Hannibal" (Discoveries... America S.)
Georgia (Discoveries... America S.)
New Mexico (Discoveries... America S.)
Florida (Discoveries... America S.)
South Dakota (Discoveries... America S.)
Driftboat Fishing 101 (How to Fly Fish S.)
Nebraska (Discoveries... America S.)
Wall Drug (Discoveries... America S.)
Tulips (Discoveries... America S.)
Iowa (Discoveries... America S.)
Missouri (Discoveries... America S.)
Colorado River (Discoveries... America S.)
SuperMuseum (Discoveries... America S.)
Illinois (Discoveries... America S.)
Michigan (Discoveries... America S.)
Ohio (Discoveries... America S.)
Delaware (Discoveries... America S.)
Virginia (Discoveries... America S.)
Louisiana (Discoveries... America S.)