References
- Bonnesen , Boggild and Ravn . 1913 . Carlsbergsfondets dybdeboring i Grondals eng ved Kobenhavn 1894–1907 Copenhagen
- Gry , H. and Sondergaard , B. 1958 . “ Flintforekomster i Danmark ” . In Committee on alkali reactions in concrete Copenhagen Progress Report D 2
- Högberg , E. 1950 . Färgningsmetoder för fältundersökningar av karbonatbergarter . Geol. Fören. Stockholm Förh , : 72 Stockholm
- Jensen , Tovborg , Wohlk , Drenck and Andersen , Krogh . 1957 . “ A classification of Danish flints etc. based on X-ray diffractometry ” . In Committee on alkali reactions in concrete Copenhagen Progress Report D 1
- Micheelsen , H. 1966 . The structure of dark flint from Stevns, Denmark . Medd. Dansk Geol. Forening , : 16 Copenhagen