Robert Pinsky reviews a translation of Adam Zagajewski’s poetry in the NYT. Among other things, he says:
The Polish pronunciation and spelling Lvov has been replaced by the Ukrainian Lviv, and behind it the linguistic and cultural echoes of Lwow and Lemberg, in an involved, blood-determined pageant of related but different names for the place.
The Polish spelling is Lwów. IPA: /lvuf/, according to Wikipedia. Here’s the poem in question, To Go to Lwów. Lvov corresponds to the Russian name of the city. It would probably be logical, generally speaking, to use the Ukrainian name transliterated as Lviv. But this is a difficult case, I admit.