Complex sentence: Oscar Almgren (November 9,1869--May 13,1945) was a Swedish prehistoric archaeologist, whose published a dissertation on Nordic types of brooches published in 1897.
Split into simpler sentences: Oscar Almgren (November 9,1869--May 13,1945) was a Swedish archaeologist specializing in prehistoric archaeology. He published a dissertation on Nordic types of brooches in 1897.