Approximately 12,000 rare books are in the LML collections. Of these, over 500 items belong to the earliest period of printing in the Philippines between the 16th and 18th centuries, which yielded dictionaries, books on cathechism, and prayer books (or incunabula) in Spanish, Tagalog, and other ethnic languags. Such literary treasures found their way into the libraries of religious houses and homes of the wealthy and educated elite.
One of the unique publications is Roberto Francesco Romolo Bellarmino’s Doctrina Cristiana, translated into Ilocano by Padre Francisco Lopez. Its cover page reads: Libro a naisuratan amin tib agas, ti Dotrina Cristiana nga naisurat iti libro.…Other rare jewels are the Relacion de las islas Filipinas published in Rome in 1604 by Padre Pedro Chirino, S.J. and various editions of Antonio de Morga’s Sucesos de las Islas Filipinas: Jose Rizal’s 1890 edition, Blair and Robertson’s 1904 edition, and W.E. Retana’s 1909 edition.
Aside from these, there are dictionaries, grammars, sermons, devotional literatures and other religious texts, travelogues, and histories of the Philippines.