TY  - RPRT
TI  - Methodological challenges in studying labour progression in contemporary practice.
AU  - Anjel Vahratian
AU  - James F Troendle
AU  - Anna Maria Siega-Riz
AU  - Jun Zhang
PY  - 2006
DO  - 10.1111/j.1365-3016.2006.00696.x
UR  - https://pubmed.ncbi.nlm.nih.gov/16420344/
ID  - 16420344
ER  -