Cunha, M., Xavier, P., Matias, J. T.-S. A., Moucho, M. and Montenegro, N. (2002) “Clinical impact of ultrasonography between the 10th and the 13th week of pregnancy”., Acta Médica Portuguesa. Lisbon, Portugal, 15(5), pp. 345–50. doi: 10.20344/amp.1975.