Shiva Purana
द्विजानां वैदिकेनापि मार्गेणाराधनं वरम् । अन्येषामपि जंतूनां वैदिकेन न संमतम् ४१ ।
The twice-born can very well worship according to the Vedic rites but not so the others who are not authorized.
english translation
dvijAnAM vaidikenApi mArgeNArAdhanaM varam । anyeSAmapi jaMtUnAM vaidikena na saMmatam 41 ।
hk transliteration by Sanscript