How It Works Illustrated Science Invention Encyclopedia Volume 5 HC

How It Works Illustrated Science Invention Encyclopedia Volume 26 HC

How It Works Illustrated Science Invention Encyclopedia Volume 7 HC

How It Works Illustrated Science Invention Encyclopedia Volume 6 HC

How It Works Illustrated Science Invention Encyclopedia Volume 17 HC

How It Works Illustrated Science Invention Encyclopedia Volume 11 HC

The Illustrated Science and Invention Encyclopedia 77’ Vol 9, 10, 15, 16, 17, 18

1989 The New How It Works Science and Invention Encyclopedia Vol 1 (Abom-Anil)