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: "What was the debut single by the singer of the 2009 single "I'll Just Hold On"?" whose answer is Austin.
Each document should contain about 30 words, and these documents should contain useful information.

Query: Taeyeon debut single
Useful Output:

Doc 1: Taeyeon debuted as a member of Girls' Generation in 2007 with “Into the New World.” She began her solo act in 2015 and has featured on
Doc 2: Taeyeon released new single #GirlsSpkOut from upcoming EP. 05/10  After already having released 3 successful EPs, she released her debut album
Doc 3: Taeyeon (SNSD/Girls' Generation, GOT the beat) to release new single Can't Control Myself on the 17th at 6 PM KST, a prerelease for her 3rd full
Doc 4: Taeyeon began her solo career in 2015 with the release of her debut EP “I”. Having sold over one million physical albums and 20 million digital
Doc 5: TAEYEON's first solo album "I" has been released. Listen and download on iTunes