@misc{AMUC_1987__52-53_186000,
     title = {[unknown]},
     journal = {Acta mathematica Universitatis Comenianae},
     pages = {155--158},
     year = {1987},
     volume = {52-53},
     url = {http://geodesic.mathdoc.fr/item/AMUC_1987__52-53_186000/}
}