<i>Trai Phum Phra Ruang</i> ("Three Worlds of Phra Ruang"), a treatise on Buddhist cosmology, composed by Phra Ruang, aka <a href="https://en.wikipedia.org/wiki/Maha_Thammaracha_I" class="extiw" title="w:Maha Thammaracha I">Lithai of Sukhothai</a>, in the year 1864 Buddhist Era (1321/22 Common Era). The work was found in a 10-volume manuscript which the Wachirayan Royal Library obtained from <a href="https://en.wikipedia.org/wiki/Phetchaburi_Province" class="extiw" title="w:Phetchaburi Province">Phetchaburi Town</a>. The manuscript, being a copy of the original document, was created by a monk called Phra Maha Chuai of Wat Klang (present-day Wat Klang Worawihan) in the year 1140 Lesser Era (2321 Buddhist Era, 1778/79 Common Era) during the reign of <a href="https://en.wikipedia.org/wiki/Taksin" class="extiw" title="w:Taksin">Taksin</a>. The work was printed for the first time by the Wachirayan Royal Library in the year 131 Rattanakosin Era (2455 Buddhist Era, 1912/13 Common Era). As regards the edition printed by the Teachers' Council of Thailand, the first edition was printed in the year 2503 Buddhist Era (1960 Common Era) and the second edition was printed as the present book.
<bdi><a href="https://en.wikipedia.org/wiki/en:Maha_Thammaracha_I" class="extiw" title="w:en:Maha Thammaracha I"><span title="Ruler of Sukhothai">Lithai</span></a>
</bdi>
<i>ไตรภูมิพระร่วง</i>. (๒๕๐๖). (พิมพ์ครั้งที่ ๒). พระนคร: โรงพิมพ์คุรุสภาลาดพร้าว.