After the passage of nearly half a century, there is probably little of value that has not yet appeared in print; certainly no battle of the First War has had more written about it than Verdun. The foregoing bibliography contains published works that have all been used to greater or lesser extent by the author, but it is by no means complete. In terms of value, the material depends greatly on the date when it was written; among the analytic works, those published either under the fog of war or very shortly afterwards have obvious limitations, while in Germany many that appeared after 1933 bear the stamp of the Nazi distortion of History, and tend to glorify German deeds at Verdun while glossing over the errors. Of the eye-witness accounts, the best are those written closest to the events, but not published until the removal of the deadening hand of censorship.Certain published sources have been used in almost every chapter. For details of operations and orders, there are the two official histories; of the Service Historique of the French Army and the Reichkriegsministerium.