Brühl / Thoma, handbook of the Wuerttemberg philately, Kreuzer period (1851-1875), Wuerttemberg handbook volume II / 1, 1975, linen letter with Praeg, here the sought and rarest bond of alignment over the stamps, postal stationery and cancel of the Kreuzer period, 283 S., with many illustration and complete with the supplement review and volume II / 2, Kreuzer period (1851-75), 1976, cancel catalogue and gazetteer with folding cards, 139 S., embossed linen, good examples.