TY  - RPRT
TI  - Travel times of P and S from the global digital seismic networks: Implications for the relative variation of P and S velocity in the mantle
AU  - H. Bolton
AU  - G. Masters
PY  - 2001
DO  - 10.1029/2000jb900378
UR  - https://pubs.usgs.gov/publication/70023278
ID  - 70023278
ER  -