The phrase "as I previously wrote" is correct and usable in written English.
You can use it to refer back to something you have mentioned earlier in your writing, often to remind the reader of a point or detail.
Example: "As I previously wrote, the deadline for the project is next Friday."
Alternatives: "as I mentioned earlier" or "as stated before".
Africa has so far been somewhat insulated from the financial crisis and its toxic assets, but as I previously wrote here, the knock on effects from a protracted recession for the cash-strapped developed economies will be felt soon enough.
As I previously wrote here, the government can produce no basis for the dossier's claim, repeated by Blair in the House of Commons, that Iraq could develop a nuclear weapon in "a year or two".
As I previously wrote in the Guardian and elsewhere, both the Bush and Obama administration have - through Saudi Arabia, Qatar and other Gulf states - fostered extremist Sunni groups affiliated to al-Qaida across the Middle East to counter Iranian influence.
But, as I previously wrote, while we were meeting in the editor's office to discuss what to do about Mahmood's misdemeanour "he wrote a letter of resignation and left the building".
As I previously wrote about in The New Yorker and in my book "The Lost City of Z," for centuries most people assumed that the Amazon was a primeval wilderness, a place in which there were, as Thomas Hobbes described the state of nature, "no Arts; no Letters; no Society; and which is worst of all, continual feare, and danger of violent death".
As I previously wrote on Forbes.com, there is a simple art to crafting a résumé.
As I've previously written, I'm generally investing in founders I know well because I've learned that a pre-existing relationship is generally more effective (for me) than an hour-long pitch.
As I've previously written, I grew up in a family of music lovers.
As I've previously written, the Xerox Palo Alto Research Center better known as Xerox PARC pioneered eight of the core components of today's computing platform: personal computers, bitmap displays, overlapping windows, graphical user interfaces, desktop publishing, object-oriented programming, laser printing, and Ethernet.
As I have previously written about on my blog, the LGBTQ community is losing its history, as well as its core values.
As I have previously written for this paper, these myths are nothing new and readily debunked.
