Sara Dolnicar, Bettina Grün,
"Including "Don't Know" Answer Options in Brand Image Surveys improves Data Quality"
, in International Journal of Market Research, Vol. 56, Nummer 1, Seite(n) 33-50, 2014, ISSN: 2515-2173
Original Titel:
Including "Don't Know" Answer Options in Brand Image Surveys improves Data Quality