Armstrong, David. “The Addressees of the Ars Poetica: Herculaneum, the Pisones, and Epicurean Protreptic.” Materiali e Discussioni 31 (1993): 185-230. This important article on the Ars poetica sheds fresh light on old problems. In particular, it discusses the specifics of the Epicurean use of free speech as therapy and its function as a model for Horace’s Ars poetica.
Brink, Charles O. “Cicero’s Orator and Horace’s Ars Poetica.” Ciceroniana 2 (1975): 97-106. An informative article clarifying issues on the relation, function, and sources of the two works.
Brink, Charles O. Horace on Poetry. Cambridge, England: Cambridge University Press, 1963-1982. The most comprehensive work on the Ars poetica. Its three volumes explore the sources of the poem and offer an edition of and extensive commentary on the text, accompanied by discussion of the poem’s literary milieu. An annotated edition of Horace’s other literary epistles complements his views on poetry.
Frischer, Bernard. Shifting Paradigms: New Approaches to Horace’s “Ars Poetica.” Atlanta: Scholars Press, 1991. This book reexamines the problems of genre, addressees, and date of the Ars poetica, reaching the innovative (but eccentric) conclusion that the poem is meant as a parody of pedantic criticism and not as a serious poetic treatise.