Linda Skrla 
Emerging Principalship, The [PDF ebook] 

This book makes a distinction between the "principal" — the man or woman who occupies the position — and the "principalship", the entire leadership function which, although overseen and coordinated by the principal, also includes activities of assistant principals, teachers, counselors, and others. It explains and applies the 21 domains recommended by the National Policy Board and demonstrates how they relate to the ISLLC standards.