
Books about Vilkko:
Wittgenstein - Ihmisluonnosta. Suomennos floora Ruokenen ja Risto Vilkko. Kustannusosakeyhtiö Otava. 1997. by PMS WITTGENSTEIN HACKER (1997)

Wiki information Vilkko:
Lauri Tapani Vilkko was a Finnish modern pentathlete who competed in the 1948 Summer Olympics and in the 1952 Summer Olympics. He won a bronze medal in the team event in 1952.