Suicide prevention for substance using youth experiencing homelessness: study protocol for a randomized controlled trial oleh Natasha Slesnick, Brittany Brakenhoff, Laura J. Chavez, Caleb L. Cuthbertson, Ruri Famelia, Xin Feng, Jodi Ford, Eugene Holowacz, Soren Jaderlund, Kelly Kelleher, Ellison Luthy, Allen M. Mallory, Alexis Pizzulo, Tatiana D. Slesnick, Tansel Yilmazer