"The Hebrew sources also recorded the name Onogundur in connection with the same events. The Muslim authors were familiar with the Danubian Bulgars by another name, which is W.n.nd.r (<Onogundur). The old Hungarian name for Belgrade was Nándorfehérvár ‘white fortress of the Nándor’, which was sometimes called Bolgárfehérvár ‘white fortress of the Danubian Bulgars’. The form Nándor may also be derived from the form Onogundur. Moravcsik identified the name Onogur with the Onogundurs, and the latter could be a Bulgar-Turkic or external designation of the Onogurs."