Books like Intensive Course in Tongan
Eric B. Shumway
Intensive Course in Tongan is 760 pages, about 13 hours 56 minutes at 250 words a minute.
12 books to read next
How long each takes
Madrigal's Magic Key to Spanish 9.1 h 
Genki 7.0 h 
Fathers and Sons 4.5 h 
French in Action 5.5 h 
The Plays of Oscar Wilde 8.2 h 
English Vocabulary in Use 3.1 h 
Remembering the Kanji I 8.9 h 
French for Dummies 7.0 h 
Spanish for Dummies 7.3 h 
Genki I 7.0 h 
German in Review 7.2 h 
Basic Chinese 5.3 h Bar height shows length. Estimated at 250 words a minute.