Some theorists didn't publish many articles; they mostly published in books, either entire books of their own or anthologies. In the Library Catalog, most of the theory books are listed under the Subject Heading "Nursing models". Books by a theorist can be found by searching for the theorist as an author (lastname, firstname).
This is a selection of books on nursing theories and models. Online books are listed first:
Dictionary of Nursing Theory and Research (online) by 
Encyclopedia of Nursing Research (online) by 
Nursing Theories (online & print) by 
Nursing Theories and Nursing Practice (online) by 
The Nature of Theoretical Thinking in Nursing (online) by 
Middle Range Theory Development Using King's Conceptual System (online) by 
Nursing Theories: the base for professional nursing practice (print) by 
Perspectives on Nursing Theory (print) by 
Nursing Theorists and Their Work (print) by 
Philosophies and Theories for Advanced Nursing Practice (print) by 
Conceptual Models of Nursing (print) by 
Understanding the Work of Nurse Theorists (print) by 
Using Grounded Theory in Nursing (online and print) by 
