@article{MAN_1963__151_161075,
     author = {B. ECKMANN and P.J. HILTON},
     title = {Group-Like {Structures} in {General} {Categories} {II-Equalizers,} {Limits,} {Lengths.}},
     journal = {Mathematische Annalen},
     pages = {150--186},
     publisher = {mathdoc},
     volume = {151},
     year = {1963},
     zbl = {0115.01403},
     url = {http://geodesic.mathdoc.fr/item/MAN_1963__151_161075/}
}