Author,Title,Edition,Publisher,Year,Series,Number,ISBN,ISSN,URL
"Langhammer, Rolf J. and Hiemenz, Ulrich","Regional integration among developing countries : opportunities, obstacles and options",,J.C.B. Mohr,1990,Kieler Studien,,3161456246,,https://cir.nii.ac.jp/crid/1130282273314723328