There is no official publication of the poem outside of the film. While you might find some online resources that claim to have the full text, those are likely fan-created or transcriptions from the movie.
If you are looking for the poem, you can try the following:
* Watch the film and transcribe it yourself. This is the most reliable way to get the exact text.
* Search online for "Mortal Storm poem" and see if any fan-made versions are available.
* Contact a film historian or archive specializing in movie-related materials. They might have a copy of the poem in their collection.
Remember that the poem's authenticity and accurate transcription might be difficult to verify outside of the film itself.