@article{CMUC_1989__30_1_a37,
     author = {Ngoc, N. V.},
     title = {The problems of complexity of almost context-free languages {[Abstract} of thesis]},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     publisher = {mathdoc},
     volume = {30},
     number = {1},
     year = {1989},
     zbl = {0688.68075},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1989__30_1_a37/}
}