1. Rock compass: a new aid for collecting oriented specimens;BIDGOOD;Bull. Geol. Soc. Am.,1959
2. Portable apparatus for collecting small oriented cores in the field;BROWN;Geol. Mag.,1963
3. Measurement of the remanent magnetization of igneous rocks;DOELL;U.S., Geol. Surv., Bull.,1965
4. Palaeomagnetic sampling with a portable coring drill;DOELL,1967
5. A portable drill rig for producing short oriented cores;GRAHAM;Trans. Geol. Soc. S. Africa,1960