Lyrics to "Lasso! di donna vana inamorato"?

I've been searching all over the net for the lyrics to a ballata by the 14th-century Italian composer Francesco Landini, "Lasso! di donna vana inamorato", and haven't been able to find them. I get the impression they're the sort of thing you wouldn't normally find on the net. I found a MIDI file supposedly containing the lyrics, but the lyrics there are only fragmentary and don't contain hyphenation or even word spacing. Does anyone have the sheet music from which they could copy the lyrics here?