Peter Duff, an accountant in Pittsburgh, was the author of several books on accounting and also the founder of a school for bookkeepers and accountants in 1840. The Duff school is significant because of its early beginnings and the fact that the school still operates today, having outlived many of its noted competitors
Givens, Horace R.
"Peter Duff: Accountant and educator,"
Accounting Historians Journal: Vol. 7
, Article 3.
Available at: https://egrove.olemiss.edu/aah_journal/vol7/iss1/3