El, A., Hösli, I., Nelle, M., Surbek, D., Wisser, J., Zimmermann, R., Fauchère, J. and Truttmann, A. (2011) “Perinatal care at the limit of viability between 22 and 26 completed weeks of gestation in Switzerland”, Swiss Medical Weekly, 141(4142), p. w13280. doi: 10.4414/smw.2011.13280.