In the past, some confusion arose regarding the year of publication, particularly of the installments 2, 5, and 7, probably caused both by the partial absence of dated forewords and of dust jackets for the individual installments, as by the fact, that the bookshop and later (1822) publisher, Lechner did not only provide installments that were sold later with a nonoriginal cover, but in a good many cases also overwrote the year of publication with the year of sale. On basis of recent investigation, the correlation between installments and the years of publication has been clarified as: