@article{10_4064_fm_84_1_47_65,
     author = {Stanis{\l}aw Godlewski},
     title = {Mutational retracts and extensions of mutations},
     journal = {Fundamenta Mathematicae},
     pages = {47--65},
     publisher = {mathdoc},
     volume = {84},
     number = {1},
     year = {1974},
     doi = {10.4064/fm-84-1-47-65},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm-84-1-47-65/}
}