Curry, S. S., Browning and the Dramatic Monologue, Haskell House, 1965.

Curry claims that Browning invented a new language
with the dramatic monologue, which might account
for why critics were slow to embrace his work.

Dupras, Joseph, "Dispatching 'Porphyria's Lover,'" in Conversations: Contemporary Critical Theory and the Teaching of Literature, edited by Charles Moran and Elizabeth F. Penfield, National Council of Teachers of English, 1990, pp. 179-86.

Dupras expresses the difficulties he encountered in
teaching "Porphyria's Lover" to his students and explains
that when a teacher forcefully determines a
poem's "meaning" to other readers, the poem dies.

Pearsall, Robert Brainard, Robert Browning, Twayne Publishers, Inc., 1974.

Pearsall provides a straightforward account of
Browning's career as a whole and attempts to say
something useful or interesting about every book and
every poem that Browning published.

Sutton, Max Keith, "Language as Defense in 'Porphyria's Lover,'" in College English, Vol...