TY  - RPRT
TI  - Age differences in fluid and crystallized intelligence.
AU  - J L Horn
AU  - R B Cattell
PY  - 1967
DO  - 10.1016/0001-6918(67)90011-x
UR  - https://pubmed.ncbi.nlm.nih.gov/6037305/
ID  - 6037305
ER  -