TY  - RPRT
TI  - The open-ring sign.
AU  - Ata Siddiqui
AU  - Anupam Sahni
AU  - Satish Khadilkar
PY  - 2005
DO  - 10.4103/0028-3886.16439
UR  - https://pubmed.ncbi.nlm.nih.gov/16010086/
ID  - 16010086
ER  -