International Standard Book Number in 1965, has – 340 indicating the publisher, 01381 their serial number, and 8 being the check digit. This can be converted to ; the check digit does not need to be re-calculated. Since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with "Bookland" European Article Number EAN-13s. An ISBN is assigned to each edition and variation (except reprintings) of a book. For example, an ebook, a paperback, and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January
What Lies Ahead also be seen in the Comic-Con trailer. The original title was seen on early marketing material for the season before the decision was made to "cannibalize" the original premiere into what would become "What Lies Ahead." Following in the tradition established by the pilot, "Miles Behind Us" was taken from the title of the first issue of the second volume of the graphic novel. In the Season 2 DVD commentary, Robert Kirkman and Glen Mazzara described the decision to retool the premiere in such a dramatic way as an amicable decision agreed upon between both the producers and AMC to