1. Les Gammes Sténographiques;Estroup,1916
2. Selective Studies of the Principle of Relative Frequency in Language;Zipf,1932
3. The Psycho-Biology of Language: An Introduction to Dynamic Philology;Zipf,1935
4. Human Bevavior and the Principle of Least Effort;Zipf,1949
5. An Informational Theory of the Statistical Structure of Languages;Mandelbrot,1953