ผลต่างระหว่างรุ่นของ "ยุทธการที่แวลเบิชด์"

* {{Cite book|ref=harv|last=Ćirković|first=Sima|authorlink=Sima Ćirković|year=2004|title=The Serbs|location=Malden|publisher=Blackwell Publishing|url=https://books.google.com/books?id=2Wc-DWRzoeIC}}

*Васил Н. Златарски, История на българската държава през средните векове, Част I, II изд., Наука и изкуство, София 1970.