This set includes 1 copy each of all 16 Pioneer and all 16 Pathfinder books (32 books total). Pioneer and Pathfinder editions present identical content at two different reading levels.
The 16 Pioneer/Pathfinder titles are:
Freedom Readers
Stories from the Underground Railroad
Coral Reefs
Freaky Frogs
Amazing Grain: The Wonders of Corn
The Fantastic Forest
Dogs at Work
The Children's Forest
Recycling Rules!
What's the Matter?
Vanishing Cultures
Culture Clash
Volcano!
Wicked Weather
The Beat Goes On
Extreme Challenge!