TY  - RPRT
TI  - Etching and bonding patterns in human sub-surface enamel.
AU  - P J Crawford
AU  - D K Whittaker
PY  - 1977
DO  - 10.1038/sj.bdj.4803989
UR  - https://pubmed.ncbi.nlm.nih.gov/334201/
ID  - 334201
ER  -