The Art of Work by Ann Marsh:

Excellent books by Mihaly Csikszentmihalyi:
Flow: The Psychology of Optimal Experience by Mihaly Csikszentmihalyi, 1991. People enter a flow state when they are fully absorbed in activity during which they lose their sense of time and have feelings of great satisfaction.

Creativity : Flow and the Psychology of Discovery and Invention by Mihaly Csikszentmihalyi, 1997. Drawing on hundreds of interviews with exceptional people, from biologists and physicists to politicians and business leaders to poets and artists, the author uses his famous “flow” theory to explain the creative process.