Two Tank Water Level Control 
References
Books
- Katsuhiko Ogata - Modern Control Engineering (2010, Prentice Hall)
- Farid Golnaraghi, Benjamin C. Kuo - Automatic Control Systems (2009, Wiley)
Video Lectures
Click here for NPTEL Lecture on PID and advance control
Click here for NPTEL Lecture on Process Control (including liquid pressure control)