Editors. "Serbia invades Bulgaria, following the union with Eastern Rumelia". The Literary Encyclopedia. First published 30 December 2011
[http://www.litencyc.com/php/stopics.php?rec=true&UID=18919, accessed 23 May 2013.]
Following the union of Bulgaria with Eastern Rumelia, Serbia launches an invasion of Bulgarian territory, but is speedily defeated and humiliated in the process, since the international powers move to recognise the new expanded state of Bulgaria.