For official, high-quality printed or digital copies for your ensemble, you can purchase the music through J.W. Pepper for roughly $5.50.
Because this is a copyrighted musical work, finding a free "Trombumba PDF" can be tricky. However, there are several reputable sources for digital scores and physical parts: trombumba pdf
Free Trombumba by George William Lotzenhiser sheet music | Download PDF or print on MuseScore.com. MuseScore.com For official, high-quality printed or digital copies for