41) Mail Art Books - Where are they?

To my knoledge in the last years there were only little publications on the subject mail-art. In the 90-ies there were some books written and published on the subject, but the new generations hardly knows about thee books. Also the accesibility of these book is low. They aren't available in libraries or bookshops........

What will happen. Do we need more books, will there eventually be more online that covers the area, or is there almost no new development in mail-art so books aren't needed? What do you think?