Original: Tibor Sekelj ( in Hungarian : Székely Tibor ) ( 14 February 1912 -- 23 September 1988 ) was an explorer , esperantist , writer and lawyer of Jewish descent .
Simplified: Tibor Sekelj ( in Hungarian : Székely Tibor ) ( 14 February 1912 -- 23 September 1988 ) was an explorer , writer and lawyer .