Doppler angle error due to refraction.

[1]  F. Dunn,et al.  Compilation of empirical ultrasonic properties of mammalian tissues. II. , 1980, The Journal of the Acoustical Society of America.

[2]  F. Dunn,et al.  Comprehensive compilation of empirical ultrasonic properties of mammalian tissues. , 1978, The Journal of the Acoustical Society of America.