@article{AL_1983_22_2_a9,
     author = {J. Mohrherr},
     title = {A conjecture of {Ershov} for a relative hierarchy fails near $\mathcal{O}$},
     journal = {Algebra i logika},
     pages = {232--235},
     publisher = {mathdoc},
     volume = {22},
     number = {2},
     year = {1983},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AL_1983_22_2_a9/}
}