Complex sentence: Other analyses of oil shale geology and chemistry were conducted during the nineteenth century at the University of Tartu by Georg Paul Alexander Petzholdt, Alexander Gustav von Schrenk, Carl Ernst Heinrich Schmidt, and Carl Friedrich Schmidt, among others.
Split into simpler sentences: Other analyses of oil shale geology and chemistry were conducted during the nineteenth century at the University of Tartu. The analysts included Georg Paul Alexander Petzholdt, Alexander Gustav von Schrenk, Carl Ernst Heinrich Schmidt, and Carl Friedrich Schmidt, among others.