In this task, you're given a passage, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.

Passage: A Winger and attacking midfielder, Jozefzoon began his career with spells at CTO '70 and AFC. He joined the Ajax Youth Academy in 2006 and signed a three-year professional contract in June 2008. Jozefzoon won his maiden call into the first team squad for the opening match of the 201011 Eredivisie season versus FC Groningen and remained an unused substitute during the 22 draw. He made his senior debut six days later, replacing Urby Emanuelson at half time during a 42 win over SBV Vitesse. He scored his only goal for the club in a 50 KNVB Becker third round win over MVV Maastricht on 22 September 2010. After five appearances during the 201011 season, Jozefzoon signed a one-year contract extension in June 2011, but spent the 201112 season away on loan and was released at the end of the season.
Link Information: none Question: Who was the head coach for Ajax Youth Academy when Jozefzoon joined?
Answer: none