| 1960 to present | 45 | May 8, 2012 |
| 1941-1960 | 44 | May 8, 2012 |
| 1918-1941 | 77 | May 8, 2012 |
| 1900-1918 | 60 | April 30, 2012 |
| 1865-1900 | 91 | April 29, 2012 |
| 1825-1865 | 82 | April 29, 2012 |
| 1763-1775 | 5 | April 29, 2012 |
| 1775-1825 | 44 | April 29, 2012 |
| Vocabulary Power Plus, Book IV, Lesson 4 | 15 | October 12, 2011 |
| The Elements 1-57, 72-89 | 75 | October 3, 2011 |
| Vocabulary Power Plus for the new SAT Book III Lesson 18 | 15 | May 23, 2011 |
| Vocabulary Power Plus for the New SAT Book III lesson 14 | 15 | March 28, 2011 |
| Vocabulary Power Plus for the new SAT Book III Lesson 5 | 15 | October 11, 2010 |
| Vocabulary Power Plus for the new SAT Book III Lesson 4 | 15 | October 3, 2010 |
| Vocabulary Power Plus for the New SAT Book III Lesson 1 | 15 | September 8, 2010 |
| Vocabulary Power Plus for the New SAT Book III Lesson 2 | 15 | September 8, 2010 |
| Vocabulary Power Plus for the New SAT Book III Lesson 3 | 15 | September 8, 2010 |
| Wordly Wise Book 8 Lesson 5 | 15 | October 10, 2009 |
| wordly wise book 8 lesson 4 | 15 | October 10, 2009 |