@ARTICLE{DasStiTru_j2009_b, author = {J{\"u}rgen~Dassow and Ralf~Stiebe and Bianca~Truthe}, title = {Two Collapsing Hierarchies of Subregularly Tree Controlled Languages}, journal = tcs, year = 2009, volume = {410}, number = {35}, pages = {3261--3271}, url = {http://dx.doi.org/10.1016/j.tcs.2009.03.005} }