Kenneth L. Rehg and Damian G. Sohl's THE 1976 PONAPEAN-ENGLISH DICTIONARY. Their 1981 Ponapean Grammar Reference is available here.
Although it is searchable through the tekinged.com search functionality, the search for Ponapean words may not work perfectly due to the fact that the Ponapean order of alphabetization is not standard.
Although tekinged.com is dedicated to the Palauan language, it is happy to provide this book as well due to the close ties between the Palauan and Ponapean languages.