@ARTICLE{TurDasSel_j2011_b, author = {Sherzod~Turaev and J{\"u}rgen~Dassow and Mohd~Hasan~Selamat}, title = {Nonterminal complexity of tree controlled grammars}, journal = tcs, year = 2011, volume = {412}, number = {41}, pages = {5789--5795}, url = {http://dx.doi.org/10.1016/j.tcs.2011.06.033} }