In pursuit of causes for the greatest mass extinction: The Permo-Triassic Boundary in the Southern Hemisphere - part 1. Fishing for fossils in 260 million years old sedimentary rocks of a former epicontinental sea in southern Brazil ; Auf der Suche nach Ur
Venustransit vom 8. Juni 2004 und «schwarzer Tropfen»: Beobachtung und weitere Hypothese der Entstehung; Transit of Venus June 8, 2004 and the «black drop phenomenon»: Observation and a further hypothesis relating to the theory of general relativity
