APA (7th ed.) Citation

Ehring, T., Zetsche, U., Weidacker, K., Wahl, K., Schönfeld, S., & Ehlers, A. (2011). The Perseverative Thinking Questionnaire (PTQ): Validation of a content-independent measure of repetitive negative thinking.

Chicago Style (17th ed.) Citation

Ehring, T., U. Zetsche, K. Weidacker, K. Wahl, S. Schönfeld, and A. Ehlers. The Perseverative Thinking Questionnaire (PTQ): Validation of a Content-independent Measure of Repetitive Negative Thinking. 2011.

MLA (9th ed.) Citation

Ehring, T., et al. The Perseverative Thinking Questionnaire (PTQ): Validation of a Content-independent Measure of Repetitive Negative Thinking. 2011.