The phrase "writing in reference to" is correct and can be used in written English.
For example, "I am writing in reference to the project you proposed last week. I am interested in learning more about your ideas."
I write in reference to Lynn Hirschberg's article (Sept . 29.
trade rules," Mr. Leavitt wrote, in reference to the World Trade Organization.
"I Learned About This in Hebrew School," someone had written, in reference to the refugees.
In his journal, he'd written, in reference to the marriage, "Every year seems the most terrible".
The writer and activist Meridel Le Sueur once wrote, in reference to artists feeding at the corporate trough, "They just want you to perfume the sewers.
"Love," Myerson writes, in reference to a relationship that has endured more than most, is just "the smallest sliver of a so much larger, more complicated thing".
"Some tourists and ingenuous foreign journalists may imagine that there is a serious separatist movement here," he writes, in reference to some aggressive regionalist graffiti.
"He said he guarded the secret hope that what happened in Apure," the rebel wrote in reference to the Venezuelan border state where the killings took place, "was the work of a force different from our own".
"Critics of free basic internet services should remember that everything we're doing is about serving people like Ganesh," he wrote, in reference to the farmer who had featured in Facebook's ad campaign.
In that same e-mail, Mr. Ahmed also wrote, in reference to another, unnamed source in Homs, that a person "who met with the Baba Amr opposition group today," said "a large shipment of weapons is coming from Libya".
