TY  - RPRT
TI  - Issues in assessing development.
AU  - D Flapan
AU  - P B Neubauer
PY  - 1970
DO  - 10.1016/s0002-7138(09)61712-x
UR  - https://pubmed.ncbi.nlm.nih.gov/4099780/
ID  - 4099780
ER  -