To begin with, we must remember that the famous Sappho 31 is preserved only in (Pseudo-)Longinus's On the Sublime, a first century work whose authorship is disputed.
Wharton, in his preface, says:
I have not concerned myself much with textual criticism, for I do not arrogate any power of discernment greater than that possessed by a scholar like Bergk. ...
Depends on how and what you count, yo. Do non-sonnets count?
Background (can be safely skipped)
Petrarch worked on his sequence to Laura, variously referred to as Il Canzoniere ("The Songbook"), Rerum Vulgarium Fragmenta ("Fragments of Common Things"), and Rime Sparse ("Scattered Rhymes"), throughout his poetic career. The ...