You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "Are Mara Santangelo and Jelena Janković both professional tennis players?" whose answer is yes.
Each document should contain about 30 words, and these documents should contain useful information.

Query: Jelena Janković tennis player
Useful Output:

Doc 1: Jelena Jankovic boasts the unenviable record of being one of only two players to have been world No. 1 without having won a Grand Slam title.
Doc 2: Former world #1 tennis player @wta · Photo by Jelena Jankovic in Dubai, United Arab Emirates. · Photo by Jelena Jankovic in Belgrade, Serbia.
Doc 3: Bio, results, ranking and statistics of Jelena Jankovic, a tennis player from Serbia competing on the WTA international tennis tour.
Doc 4: Jelena Jankovic was born February 28, 1985, in Belgrade, Serbia. She is one of the top female tennis players in the world and former world's number one.
Doc 5: Jelena Jankovic · Country: Serbia · Date of birth: 28 February 1985 · Place of birth: Belgrade · Height: 1.75 m · Weight: 65 kg.