id	domain	url
caste-450	doi.org	https://doi.org/10.1177/2394481118774489
caste-450	repository.upenn.edu	https://repository.upenn.edu/psc_publications/50
caste-450	doi.org	https://doi.org/10.1136/jech.2006.047647
caste-450	doi.org	https://doi.org/10.1186/s41118019-0054-1
caste-450	doi.org	https://doi.org/10.1136/bmj.c2050