The following publications may be helpful to adults working with adolescents (ages 12-18) in a Montessori context:
From Childhood to Adolescence by Maria Montessori
The Fifth Adolescent Colloquium special issue of The NAMTA Journal (Summer, 2009).
The Fourth Adolescent Colloquium special issue of The NAMTA Journal (Summer, 2008).
The Third Adolescent Colloquium special issue of The NAMTA Journal
The First Adolescent Colloquium (proceedings of the first Colloquium, 1996)
The Montessori Adolescent: Analysis in Retrospect special issue of The NAMTA Journal
A Comparison of Montessori and Traditional Middle Schools: Motivation, Quality of Experience, and Social Context by Kevin Rathunde (available for download as a pdf file)
The Evolution of a Montessori High School, the 2013-2015 supplement to The Whole-School Montessori Handbook
NAMTA's Role in the History of Montessori Adolescent Programming
The AMI Montessori Orientation to Adolescent Studies
Print/Video Resources | Whole School Resources
Hershey Montessori School Adolescent Community on the Farm | Montessori High School at University Circle
Hershey Montessori Training Institute