ADAC: Visser to stay with Lotus in 2013. [w:] ADAC Formel Masters [on-line]. 26 March 2013. [dostęp 2013-03-27]. Cytat: Visser is joined by Dutch compatriot Indy Dontje who is also about to start his second year in Formel ADAC racing.
ADAC: Start of season second half. [w:] ADAC Formel Masters [on-line]. 8 August 2013. [dostęp 2013-08-10]. Cytat: This weekend, the team will put their trust in young Kuwaiti driver, Zaid Ashkanani (17, Kuwait, HS Engineering).