A Grammar of the Old Friesic Language
Adley H. Cummins
The grammar of the Old Friesic language, which was already known to the Romans who called them Frisii focuses on phonology, nominal and verbal morphology. Index (Re-edition; originally published 1881 in London; written in English).
ISBN 978 3 86290 074 9. LINCOM Gramatica 68. 77pp. 2010.