It is right that you have to purchase the questionnaire at mindgarden.com because of the copyright as Adelheid Nicol already mentioned. Unfortunately Michael Leiter could not provide it for my research.
Concerning MBI-ES (Educators Survey) which is specific for teachers, there is an adapted free German version which is part of the "Skalen zur Erfassung von Lehrer- und Schülermerkmalen" by Jerusalem & Schwarzer (1999). You can download it here: http://www.psyc.de/skalendoku.pdf