Books about the Alexander Technique published in the dutch language:

Ailsa Masterton, De Alexander Techniek
ISBN 90-5495-250-4
an introduction to the Alexander Technique available in the bookstore

Elizabeth Langford, Denken en bewegen
ISBN 90-441-1162-0
available in the bookstore

Glenn Park, De Alexander Techniek in een nieuw licht
ISBN 90-202-52437
no longer available

Judith Leibowitz , De Alexander Techniek
ISBN 90-229-8145-2
no longer available

F.M Alexander has written four books:

Man's Supreme Inheritance
Constructive Conscious Control of the Individual
The use of the Self
The Universal Constant in Living

These books are only availible in english. The most easy to read and straigth-forward book
is The Use of the Self (ISBN 0-575-03720-2).

In the english language there are a lot of books about the Alexander Technique, dealing with a lot of different subjects. You can order them at STAT-books (www.stat.org.uk).
A few interesting ones I list below:

The art of Swimming , Steven Shaw en Armand D' angour
Tjee Alexander Technique applied to swimming.

Curiosity Recaptured, Exploring Ways We Think and Move, edited by Jerry Sontag
Fourteen essays related to the Alexander Technique.

Indirect Procedures, a Musicians guide to the Alexander Technique, Pedro de Alcantara

Thinking Aloud, Talks on Teaching the Alexander Technique, Walter Carrington
Twenty-five talks on teaching the Alexander Technique.