TY  - RPRT
TI  - Letter: Book prices.
AU  - J W Nicholas
AU  - J B Penfold
PY  - 1975
DO  - 10.1016/s0140-6736(75)92856-1
UR  - https://pubmed.ncbi.nlm.nih.gov/46980/
ID  - 46980
ER  -