"id","author_first1","author_last1","title","year","publication","place","keyword0","keyword1","keyword2","keyword3","keyword4","keyword5","keyword6","keyword7","keyword8","type" "1851","Emil","Betzler","Sozialer Umbruch und Kulturlandschaftswandel in Südarabien. Agrargeographische Untersuchungen im Umland von ana (Arabische Republik Jemen)","1987","Jemen-Studien Band 5","Wiesbaden","Agriculture","Change","Development","Glossary","Markets","Modernization","PDRY","Qat","Terms","report"