English: Serb lands in the late 9th and 10th century according to some Serbian sources, but internationally not recognized, and not based on primary sources in which there's no mention of any expansion during Časlav in the early and mid-10th century during whom could only happen enlargement of the Serbian borders. Rascia and possibly Bosnia (with disputable border with Croatia) were not part of Serbia at the time.
This map has been uploaded by Electionworld from en-two.iwiki.icu to enable the Wikimedia Atlas of the World. Original uploader to en-two.iwiki.icu was PANONIAN, known as PANONIAN at en-two.iwiki.icu. Electionworld is not the creator of this map. Licensing information is below.
References
Istorijski atlas, Geokarta, Beograd, 1999.
Miloš Blagojević, Srpska državnost u srednjem veku, Beograd, 2011.
Vladimir Ćorović, Ilustrovana istorija Srba, knjiga prva, Beograd, 2005.
Petrit Imami, Srbi i Albanci kroz vekove, Beograd, 2000.
Školski istorijski atlas, Zavod za izdavanje udžbenika SR Srbije, Beograd, 1970.
The Times, Atlas Svjetske Povijesti, Cankarjeva založba, Ljubljana - Zagreb, 1986.
Sima M. Ćirković, Srbi među evropskim narodima, Beograd, 2004.
Sve srpske mape - od šestog veka do Pariza, Specijalno izdanje BLICA, Decembar 1995. godine.
The original image seems to had been saved as JPEG, and the previous uploader had simply converted it to PNG. I have greatly reduced image size by removing JPEG artifacts, reducing color domain, etc.