Bolt, B. A. (1982). "The Constitution of the Core: Seismological Evidence". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 306 (1492): 11–20. Bibcode:1982RSPTA.306...11B. doi:10.1098/rsta.1982.0062. S2CID120731079.
Bolt, B. A. (1982). "The Constitution of the Core: Seismological Evidence". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 306 (1492): 11–20. Bibcode:1982RSPTA.306...11B. doi:10.1098/rsta.1982.0062. S2CID120731079.
oxforddnb.com
Cook, Alan [rev.], "Jeffreys, Sir Harold (1891–1989)", Oxford Dictionary of National Biography, Oxford University Press, 2004; online edition, September 2004. Retrieved 1 January 2023. (subscription required)
Bolt, B. A. (1982). "The Constitution of the Core: Seismological Evidence". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 306 (1492): 11–20. Bibcode:1982RSPTA.306...11B. doi:10.1098/rsta.1982.0062. S2CID120731079.