Cenozoic Paleobotanical Resource Inventory of the National Park System T. P. Matel, J. S. Tweet, V. L. Santucci E-Book (epub)

Inverse Methods in Electromagnetic Imaging Wolfgang-M. Boerner, Hans Brand, Leonard A. Cram E-Book (pdf)

Geologie des niederrheinisch-westfälischen Steinkohlengebietes Paul Kukuk, H. Breddin, W. Gothan E-Book (pdf)