TY - BOOK AU - Hartmann, Paul TI - Media research : aspects of method PB - Open University Press PY - 1987 T2 - Communication and education VL - block 6 . Communication, media and society ; unit 21 EP - 27 p. UR - https://ci.nii.ac.jp/ncid/BA11413276 SN - 0335133711 ER -