^Fischer، Steven Roger (2004). History of Reading. Globalities Series. Reaktion Books. صفحة 282. ISBN9781861892096. اطلع عليه بتاريخ 17 فبراير 2013. [...] in 1867, with the coming into force of the constitution of the Northern German Federation [...], works by German authors deceased for 30 years or more officially became public domain. Entire libraries of very cheap paperback editions of German classics immediately flooded the market. And so Reclam, too, extended his paperback idea with the new series 'Universal-Bibliothek' (Universal Library') [...]. Thousands of titles eventually followed, which included nearly all the world's great literature. In this way, and despite most Western countries' imitations, Reclam paperbacks became the world's foremost paperback series.