67 books • 6 series
New Jersey (Discoveries... America S.)
Maryland (Discoveries... America S.)
Washington DC (Discoveries... America S.)
Marbles (Discoveries... America S.)
Tennessee (Discoveries... America S.)
West Virginia (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.)
Pioneer Auto Show (Discoveries... America S.)
Tulips (Discoveries... America S.)
Iowa (Discoveries... America S.)
Missouri (Discoveries... America S.)
Colorado River (Discoveries... America S.)
Mark Twain Himself (Discoveries... America S.)
Matchstick Marvels (Discoveries... America S.)
SuperMuseum (Discoveries... America S.)
Illinois (Discoveries... America S.)