Overview Kosovo Stamp Catalogues
Guernsey Stamp Catalogues (books)

Kosovo
Kosovo Stamp Auctions/Marketplaces
Catawiki
Ebay
Stampden Kosovo Stamps

Kosovo Online Stamp Catalogues
Michel (German/English) – Most complete online stamp catalogue with actual prices (subscription required)
Colnect (all language) – Colnect (premium) has auto-matching, best matches and an extensive free stamp catalogs
Posta Kosoves (English/Albanese/Serbian) – All stamps since 2000
