1. Sur la conduite des points sous les transformations homéomorphes de l’espace;Barbachine, E.;C. R. (Doklady) Acad. Sci. URSS (N. S.),1946
2. American Mathematical Society Colloquium Publications, Vol. IX;Birkhoff, George D.,1966
3. Almost periodic points with respect to transformation semi-groups;Gottschalk, W. H.;Ann. of Math. (2),1946
4. Almost periodicity, equi-continuity and total boundedness;Gottschalk, W. H.;Bull. Amer. Math. Soc.,1946
5. Recursive properties of transformation groups. II;Gottschalk, W. H.;Bull. Amer. Math. Soc.,1948