Pettersen, Bjorn Ragnvald |
Astronomy in a shipping nation : harbour observatories in Norway, 1850-1900 / Bjorn Ragnvald Pettersen |
In: Who needs scientific instruments. p. 67-72 |
Pettersen, Bjorn Ragnvald |
Observations of Galilean moons for geographical longitude determinations in Norway, 1761-1804 / Bjorn Ragnvald Pettersen |
In: Astronomy and its instruments before and after Galileo. p. 345-354 |
The observatory in Oslo : attracting youth to the sciences / Bjorn Ragnvald Pettersen ... [et al.]. |
In: Astronomy and its instruments before and after Galileo. p. 461-469 |