Warttig SL, Forshaw MJ, South J, White AK. New, normative, English-sample data for the Short Form Perceived Stress Scale (PSS-4). J Health Psychol. 2013 Dec;18(12):1617-28. doi: 10.1177/1359105313508346
Lovas K, Geher P, Whalley D, McKenna S, Meads D, Kalo Z. Hungarian adaptation of a disease-specific quality-of-life questionnaire in patients with ankylosing spondylitis. Orv Hetil. 2002 Aug 11;43(32):1893-7.