The phrase "as the definitive source" is correct and usable in written English.
It can be used when referring to a particular reference or authority that is considered the most reliable or conclusive on a subject.
Example: "The research paper cites the National Institute of Health as the definitive source for information on the effects of the drug."
Alternatives: "as the authoritative source" or "as the primary reference".
You position the site as the definitive source of Republican campaign information in the area.
The site is widely recognized as the definitive source of information on this tragedy.
The line is from the Gospel of Matthew and has often been cited as the definitive source for the deicide accusation against the Jews.
Its immediate sequel will offer a census of all known copies (the first attempted since Sir Sidney Lee's in 1902, and a good deal more ambitious in scope), and, as the definitive source of information about the condition, provenance, binding and whereabouts of each extant specimen of F1, it will presumably be seized on at once as the bible of the up-market contract book thief.
We will leverage these strengths to become a more integral part of our listeners' lives and reinforce our position as the definitive source for audio advertising".
"You did all that while burnishing AP's reputation as the definitive source for news".
"Together, we create the definitive source for Internet measurement and analysis as well as the ultimate platform for long-term growth," says Tod Johnson, chairman and chief executive of Media Metrix.
Judith Fitzgerald of The Philadelphia Inquirer, who predicts that Street Gang will become the definitive source of the show, calls "a compulsively readable compendium of all things Sesame Street", as well as informative, heartbreaking, hilarious, and eye-opening".
In contrast, "American Top 40" under Kasem was the definitive source, something we all agreed on, and each week as he ran through Billboard's pop singles chart there was a palpable sense of anticipation.
It was the definitive source for those of us studying metallurgy in the 1950s.
[ image: /photos/59095882c14b3c606c104c80] Here is the definitive source on the full range of Bimbo pastries.
