@article{WyschkonKohnBallaschketal.2009,
  author    = {Wyschkon, Anne and Kohn, Juliane and Ballaschk, Katja and Esser, G{\"u}nter},
  title     = {Sind Rechenst{\"o}rungen genau so h{\"a}ufig wie Lese-Rechtschreibst{\"o}rungen?},
  issn      = {1422-4917},
  doi       = {10.1024/1422-4917.37.6.499},
  year      = {2009},
  abstract  = {Is a specific disorder of arithmetic skills as common as reading/spelling disorder?Background: Referring to the prevalence rates of learning disorders in the research literature, the numbers of mathematics disorder and reading/ spelling disorder are often reported to be identical. However, the correlation between intelligence level and reading/ spelling skills is much weaker than between intelligence and arithmetic skills. If the same definition criterion is applied to both disorders, a lower prevalence rate for mathematics disorder should be expected. Objective: Are there differences in the prevalence estimates for learning disorders depending on the definition criterion? Method: A large representative sample of German students (N = 1970) was used to review the hypothesis. Results: Depending on the definition criterion, we could show a prevalence range of mathematics disorder between 0.1\% and 8.1\% in the same sample. Using the same definition criterion for both learning disorders, there are two to three times as many students with reading/spelling disorder than those with mathematics disorder. Discussion: Whenever children with reading/spelling disorder are compared to children with mathematics disorder, the same definition criterion has to be applied.},
  language  = {de}
}
@article{StraubHaenschBallaschketal.2009,
  author    = {Straub, Hans-Beatus and Haensch, Sylvana and Ballaschk, Katja and Esser, G{\"u}nter},
  title     = {The Brandenburg questionnaire for quality of life in epilepsy patients : a new, short and valid instrument},
  issn      = {0013-9580},
  doi       = {10.1111/j.1528-1167.2009.02156.x},
  year      = {2009},
  language  = {en}
}