It has several publication dates listed on the internet: March 2004, Jan 2005, Jan 2006 - and Dec 2010.
Its ISBN, which looks to be the same all the way through, is only 10 digits, (3897901625), which means it was assigned prior to 2007. Either it was published in very small numbers each time, or the publication has been beset with problems, such as clearing copyright on images and newer catalogues, which have shifted the release several times.