Following websites are excellent resources for nursing theory and information about nursing theorists, including Nightingale, Watson, Henderson, Peplau, Leininger, Benner and others:
Here are some subject headings in CINAHL. You have many options.
Nursing Theorists and Their Work by 
Caring Science, Mindful Practice by 
A History of American Nursing by
A History of American Nursing: Trends and Eras is the first comprehensive nursing history text to be published in years. It provides a historical overview essential to developing a complete understanding of the nursing profession. For each key era of U.S. history, nursing is examined in the context of the sociopolitical climate of the day, the image of nurses, nursing education, advances in practice, war and its effect on nursing, licensure and regulation, and nursing research and its implications. From early nursing to Nightingale's influence, through two world wars to today, this text engages students in an exploration of nursing's past while connecting it to nursing practice in the present.A History of American Nursing: Trends and Eras is designed to inform and empower today's student nurses as they help to create the future of nursing.
Analyzing and Constructing the Conceptual and Theoretical Foundations of Nursing by 
Reflecting on Presence in Nursing: A Guide for Practice and Research by 
