* No central database: There's no single, comprehensive database that tracks every book published on leadership.
* Diverse definitions: Leadership is a broad topic with many different approaches and perspectives. Books can focus on specific leadership styles, industries, or even historical figures.
* Constant publications: New leadership books are being published all the time, making it a constantly changing number.
However, we can say that thousands upon thousands of books have been written on leadership. It's a popular topic that continues to generate interest and new perspectives.
Rather than focusing on a specific number, it's more helpful to consider the vastness of the literature on leadership. This means that there are many resources available to explore different ideas and approaches to leadership.