The stepladder sign
Crossref DOI link: https://doi.org/10.1007/s00261-016-0933-2
Published Online: 2016-10-07
Published Print: 2017-03
Update policy: https://doi.org/10.1007/springer_crossmark_policy
Hiatt, Kevin D.
Dyer, Raymond B.
License valid from 2016-10-07