Spontaneous regression of a yolk sac associated with embryonic death.

@article{Mara2000SpontaneousRO,
  title={Spontaneous regression of a yolk sac associated with embryonic death.},
  author={E Mara and Gregory S. Foster},
  journal={Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine},
  year={2000},
  volume={19 9},
  pages={655-6}
}