There is a publishing house (with about 30 different publishing names) that publish books on sometimes reasonably obscure/technical aspects of WW2 (in addition to other fields).
The downside is that the books are literally a group of articles copy and pasted from wikipedia directly into book format and given a generic abstract design book cover.
Not only are the articles not validated but there is even no proof reading for spelling punctuation etc. I came across this on another forum I use (WAF) where one poster had previously posted articles about a burial site of German soliders which he personally researched, he wrote some posts on this subject in that forum in a thread, then decided to put them on wiki in article format. Then found out his 'book' on sale without any advance notice of any kind. This persons writing was included in a book for which no royalties or credit was given whatsoever.
The publishers excuse is that if you put it on wiki it's free for any and all kinds of commercial use. It is probably legal (though unchallenged at this point) but hardly a reputable practice.
I have seen several of these on amazon, mostly for approx €15 or so but some are selling for €60. So buyer beware !
Anyway here is the wiki page on the subject :
Wikipedia content duplication
 Alphascript and Betascript Publishing
Alphascript Publishing (created in April 2009), Betascript Publishing (created in January 2010), Fastbook Publishing (created in July 2009) and Doyen Verlag (created in April 2010) are imprints of VDM Publishing, which publish and sell collections of freely available Wikipedia articles as expensive printed-on-demand books. Alphascript lists amazon.de, amazon.co.uk, amazon.com, knv.de, libri.de, schaltungsdienst.de, bod.de, VDM, VSG, ingrambook.com, umbreit.de, reha Marketing, smartprofessionals.de, xing.de, lightningsource.com, bischoffundpartner.de as business partners. These books have been inadvertently purchased by German libraries at the request of their patrons, and by Flemish libraries.
History of Ghana: a collection of Wikipedia articles published as a book
These titles are published as edited by Frederic P. Miller, Agnes F. Vandome, and John McBrewster who are also listed as authors. As of November 2010, there are over 77,000 titles listed on Amazon.com. Betascript lists "Lambert M. Surhone, Miriam T. Timpledon, Susan F. Marseken, Mariam T. Tennoe and Susan F. Henssonow" as editors, giving an additional 69,500 titles as of November 2010.
Alphascript defends its publishing methods: "There is hardly another platform for quick and better processing of information than Wikipedia" for customers "who want to be informed on a specific subject" in book form, though they can "have online everything free of charge." In response to an interview question about whether all of Alphascript’s books take their content from Wikipedia, Alphascript responded, "Yes, since we believe that the quality of the Wikipedia-articles is so good that it is worthwhile creating books with them. Wikipedia themselves give an impulse for this. The articles published on their sites are free in every respect and without any limitations as to further use. All authors participating in texts of Wikipedia know this or should at least know it." In response to whether this should be made clear in the product description, Alphascript responded, "It is pointed out in every Alphascript book that contents are Wikipedia articles. Do we now have to write in Amazon-books: “Attention! Books contains Wikipedia!”? Then other publishing houses would have to point out in their books: “Attention! Book contains nonsense!”, or: “Attention! Book has only sex-scenario!” VDM have also been criticised for "fraud" in selling printed Wikipedia articles to libraries. A further criticism is their large number of works (22,000) edited by the same editor(s).