Pay for the $3.99 edition from a known guitar sheet music site. The free PDFs circulating are often riddled with errors.
If you’re serious about conquering one of the most beautiful and challenging works for solo guitar, hunt down a reputable PDF edition of Un sueño en la floresta . Just be prepared to shed it for six months before it sounds like a dream, not a nightmare.
As a long-time student of classical guitar, I’ve always held Agustín Barrios Mangoré’s Un sueño en la floresta ("A Dream in the Forest") as the holy grail of romantic tremolo studies. Finding a reliable, high-quality PDF of this piece is surprisingly difficult—but this particular edition gets most things right.