So-called "absence" of the leaflets of the pulmonary valve.

@article{Acar2008SocalledO,
  title={So-called "absence" of the leaflets of the pulmonary valve.},
  author={Philippe Acar and Sylvia Abadir and Gilles Brierre},
  journal={Cardiology in the young},
  year={2008},
  volume={18 5},
  pages={535-6}
}