Dordt College Press have recently published a new book on D. H. Th. Vollenhoven by Kor Bril Vollenhoven's Problem-Historical Method (Dordt College Press, June 2005)
I have just ordered mine from amazon.
Two more books by Vollenhoven due out at the end of August:
Introduction to Philosophy (pbk)
Isagôgè Philosophiae: Introduction to Philosophy (Hbk)
The paperback is the English only of Vollenhoven's intro, the hardcover has both Dutch and English. Preface by Calvin Seerveld and (long) Foreword by Anthony Tol.