@article{specht_2004,  title={Compact and user-friendly ultrasound acquisition systems optimized for field recording},  volume={76},  ISSN={0001-3765},  url={https://doi.org/10.1590/S0001-37652004000200040},  DOI={10.1590/S0001-37652004000200040},  number={2},  journal={Anais da Academia Brasileira de Ciências},  publisher={Academia Brasileira de Ciências},  author={Specht, Raimund},  year={2004},  month={Jun},  pages={453–454} }