Overview Romania Stamp Catalogues
Romania Stamp Catalogues (books)

Romania
Romania Stamp Auctions/Marketplaces
Catawiki
Ebay
Stampden Romania Stamps

Romania 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
Romaniastamps (English) – All stamps since 1990