References
- IUGG . 1957 . Proceedings of Toronto Meeting of the International Union of Geodesy and Geophysics Resolution No. 46
- Gilman , L. and Scheepers , G. L. M. 1959 . ‘Geomagnetic observations at Gough Island and Tristan da Cunha’ . Int. Hydr. Rev. , XXXVI : 161 – 166 .