TY  - RPRT
TI  - Mandibular first premolar with three root canals.
AU  - M Hülsmann
PY  - 1990
DO  - 10.1111/j.1600-9657.1990.tb00416.x
UR  - https://pubmed.ncbi.nlm.nih.gov/2133309/
ID  - 2133309
ER  -