Yan Zi and Tom Okker, have which mutual occupation?
tennis player
Title: 1980 U.S. Pro Indoor – Doubles
Passage: Wojtek Fibak and Tom Okker were the defending champions, but Okker did not participate this year.  Fibak partnered Heinz Günthardt, losing in the semifinals.
Title: Tom Okker
Passage: Thomas Samuel Okker (born 22 February 1944) is a former Dutch tennis player.  He was ranked among the world's top 10 singles players for seven consecutive years, 1968–74, reaching a career high of World No. 3 in 1969.  He also was ranked World No. 1 in doubles in 1969.
Title: Yan Zi (tennis)
Passage: Yan Zi (; ; born November 12, 1984), is a retired Chinese-born Hong Kong female professional tennis player.
Tom Okker Yan Zi (tennis)