1. Palynological investigations in the Jurassic of the North Sea;Abbink,1998
2. The Jurassic of Kuhn Ø, North-East Greenland;Alsgaard,2003
3. Standard Practice for Preparing Coal Samples for Analysis;ASTM International, Designation: D2013/D2013M-11,2011
4. Standard Practice for Preparing Coal Samples for Microscopical Analysis by Reflected Light;ASTM International, Designation: D2797/D2797M–11a,2011
5. Standard Test Method for Moisture in the Analysis Sample of Coal and Coke;ASTM International, Designation: D3173-11,2011