@article{MZ_1984__186_173450,
     author = {Heiner Zieschang and Donald J. Collins},
     title = {Rescuing the {Whitehead} {Method} for {Free} {Products,} {II:} {The} {Algorithm.}},
     journal = {Mathematische Zeitschrift},
     pages = {335--362},
     publisher = {mathdoc},
     volume = {186},
     year = {1984},
     zbl = {0542.20012},
     url = {http://geodesic.mathdoc.fr/item/MZ_1984__186_173450/}
}