Series
| Series Name | Release Date | Product Count |
|---|---|---|
| True Spy Stories | 2021-01-01 | 7 |
| True Stories, Real People | 2016-01-01 | 7 |
| Twelve Magic Months | 2014-08-01 | 13 |
| Understanding Idioms | 2023-01-01 | 13 |
| Understanding the Basics | 2018-01-01 | 11 |
| Unsolved Mysteries | 2015-08-01 | 11 |
| U.S.A. Travel Guides | 2017-08-01 | 53 |
| Weird-but-True Facts | 2013-01-01 | 16 |
| Weird Sports | 2011-01-01 | 7 |
| Welcoming the Seasons | 2017-01-01 | 47 |
| Women's Professional Basketball | 2020-01-01 | 7 |
| Wonders of Space | 2016-01-01 | 8 |
| WordBooks/Libros de Palabras | 2024-01-01 | 17 |
| Youth Sports | 2023-08-01 | 13 |