sentences:  The third principal work is "Den oldnorske og oldislandske litteraturs historie", a detailed history of Old Norse literature.Finnur was an unusually prolific scholar, preparing editions of, among other works, numerous Icelanders' sagas, Kings' sagas, "Rímur" (along with a dictionary of "rímur") and the Eddas.A skilled polemicist, he defended his belief in the historical accuracy of the sagas and the antiquity of the Eddic poems in debates with other scholars.