TY - JOUR AU - Bussmann, Johannes PY - 2013 M3 - Opinion TI - One plus one equals three (or more …): combining the assessment of movement behavior and subjective states in everyday life JO - Frontiers in Psychology UR - https://www.frontiersin.org/articles/10.3389/fpsyg.2013.00216 VL - 4 SN - 1664-1078 ER -