TY  - RPRT
TI  - Videotaped behavioral observations: enhancing validity and reliability.
AU  - J H Elder
PY  - 1999
DO  - 10.1016/s0897-1897(99)80273-0
UR  - https://pubmed.ncbi.nlm.nih.gov/10589109/
ID  - 10589109
ER  -