I recently got a book called "Zur Arbeit nach Holland".
It is beautifully illustrated and provides the results of a the research by
the universities of Osnabr�ck and Amsterdam on the background and motifs of
the "Hollandg�ngerei"; the seasonal work by people from the Osnabr�ck
region in Holland.
The book is published (ISBN 3-00-007774-X) by the University of Osnabr�ck
and accompanies an exhibition held in the fall of 2000.
It is written in two languages (German and dutch) and in my opinion a "must
read" for anyone interested in the subject.