1. T.L. Hill, An Introduction to Statistical Thermodynamics, Dover, New York, 1986.
2. The terms “vertical” and “lateral” are used with the meaning of “normal” to the surface and “non-vertical”, respectively.
3. Two-dimensional phase transitions as displayed by adsorption isotherms on graphite and other lamellar solids
4. Stepwise isotherms and phase transitions in physisorbed films
5. The surfaces of highly dispersed solids may display many pathological behaviours. To avoid confusion when using terms like smooth, flat, rough, etc., we shall systematically use the following definitions: according to its fractal dimension D a surface is classified either as smooth when D=2 or as fractal when 2