The position of the Roode en witte roos [by Lambert van den Bos] in the Saga of King Richard III /
Campbell, Oscar James.
Bos, Lambert van den.Roode en witte roos.
New York :  AMS P., 
1971.
Facsimile reprint of the Madison, 1919 edition in the series University of Wisconsin studies in language and literature, no. 5.