Bittmann, Felix. "9. Matching". Stata: A Really Short Introduction, Berlin, Boston: De Gruyter Oldenbourg, 2019, pp. 134-140. https://doi.org/10.1515/9783110617160-009
Bittmann, F. (2019). 9. Matching. In Stata: A Really Short Introduction (pp. 134-140). Berlin, Boston: De Gruyter Oldenbourg. https://doi.org/10.1515/9783110617160-009
Bittmann, Felix. "9. Matching" In Stata: A Really Short Introduction, 134-140. Berlin, Boston: De Gruyter Oldenbourg, 2019. https://doi.org/10.1515/9783110617160-009