[Published 1951, copyright not renewed]
This book, which appears for the first time on the Internet at Sacred Texts, contains the traditional Creation and Geneological Chant of the Hawaiian royal family, and Beckwith's extensive textual, anthroplogical, and historical commentary. This is one of the few source documents available in the realm of Polynesian religion, and it is stunning. The full Hawaiian version of the chant is included.
Very few works this recent are yet in the public domain. This book is in the public domain because it was not renewed in a timely fashion as the US copyright law required at the time.