@inbook{403665, title = {[Ob\'alka]}, booktitle = {Dokonal\'e a spriatelen\'e \v c\'\i sla}, series = {GDML\_Books}, publisher = {Mlad\'a fronta}, address = {Praha}, year = {1969}, pages = {[i]-[ii]}, url = {http://dml.mathdoc.fr/item/403665} }
(éd.). [Obálka], dans Dokonalé a spriatelené čísla, GDML_Books, (1969), pp. [i]-[ii]. http://gdmltest.u-ga.fr/item/403665/