Drobnig, Ulrich MPI for Comparative and International Private Law, Max Planck Society;
https://max-eup2012.mpipriv.de/index.php/Guarantee,_Independent (Any fulltext)
Drobnig, U. (2012). Guarantee, Independent. In J. Basedow, K. J. Hopt, & R. Zimmermann (Eds.), The Max Planck Encyclopedia of European private law (pp. 806-807). Oxford: Oxford University Press.