Complex sentence: Youngest of the 3 illustrious Biržiška brothers, sons of Antanas and Elžbieta Biržiska, he did study mathematics and engineering at the University of St.Petersburg in 1904-08 and Petrograd Institute of Technology 1909-14.
Split into simpler sentences: Youngest of the 3 illustrious Biržiška brothers, sons of Antanas and Elžbieta Biržiska. Studied Mathematics and Engineering at the University of St.Petersburg 1904-08 and Petrograd Institute of Technology 1909-14.