Prescribing differences in family practice for diabetic patients in Germany according to statutory or private health insurance: the case of DPP-4-inhibitors and GLP-1-agonists - Laux, Gunter; Berger, Sarah; Szecsenyi, Joachim; Kaufmann-Kolle, Petra; Leutgeb, Rüdiger (BioMed Central; Springer, 2016)