Brett, J. P. (1987). Pechen: The Bontok peace pact institution. Cordillera Studies Center, University of the Philippines College Baguio.
Lua i Stíl Chicago (17ú heag.)Brett, June Prill. Pechen: The Bontok Peace Pact Institution. Baguio City: Cordillera Studies Center, University of the Philippines College Baguio, 1987.
Lua MLA (9ú heag.)Brett, June Prill. Pechen: The Bontok Peace Pact Institution. Cordillera Studies Center, University of the Philippines College Baguio, 1987.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.