TY  - RPRT
TI  - [Difficulty in determining ultrasonic attenuation values from selective echograms].
AU  - M Petzold
AU  - K Gräfenstein
AU  - K V Jenderka
AU  - K P Richter
PY  - 1990
UR  - https://pubmed.ncbi.nlm.nih.gov/2236549/
ID  - 2236549
ER  -