TY  - RPRT
TI  - Proceedings: Scientific communications.
AU  - J Z Heckmatt
AU  - R A Shanks
PY  - 1975
DO  - 10.1136/adc.50.11.903
UR  - https://pubmed.ncbi.nlm.nih.gov/1108809/
ID  - 1108809
ER  -