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2. Evaluation subgroups of homotopy groups;Gottlieb;Amer. J. Math.,1969
3. Covering transformations and universal fibrations;Gottlieb;Illinois J. Math.,1969
4. Certain subgroups of homotopy groups;Kim;J. Korean math. Soc.,1984
5. The relative evaluation subgroups of a CW-pair;Lee;J. Korean Math. Soc.,1988