1. Dynamical Systems;Birkhoff,1966
2. Dynamics in One Dimension;Block,1992
3. Topology;Dugundji,1966
4. Orbit-closure decompositions and almost periodic properties;Gottschalk;Bull. Amer. Math. Soc.,1944
5. Almost period points with respect to transformation semi-groups;Gottschalk;Ann. of Math.,1946