An outstanding and ingenious work
G.) The magnum opus in English on Turkish poetry is E.
His magnum opus dates from this period.
His magnum opus is the Sefer Miklol, "Book of Completeness."
He wrote abundantly in prison; his magnum opus was a history of Sweden in Latin, but he has also left, in Swedish, two important rhyme-chronicles.
And from him we have immense amounts to learn, as Simon Schama's recent magnum opus vividly demonstrates.