@ARTICLE{Dem88a,
  author = {Demuth, Osvald},
  title = {Remarks on the structure of tt-degrees based on constructive measure
	theory},
  journal = {Commentationes Mathematicae Universitatis Carolinae},
  year = {1988},
  volume = {29},
  pages = {233--247},
  number = {2},
  keywords = {bib,rus}
}