Linked from
The 15 pages that link to Tanka, each with the reason it gives.
WakaBroader topic: This is the waka form most commonly identified with the thirty-one-mora pattern.
Kokin WakashūBroader topic: Most poems in the anthology use this compact five-line form.
Man'yōshūBroader topic: Many anthology poems use the compact form that became known as tanka.
Fujiwara no TeikaBroader topic: This compact form is the main structure of Teika’s surviving poetry.
Ariwara no NarihiraBroader topic: This compact form underlies many poems attributed to Narihira.