Akbilgic, O. ., MR, L. . , Jr., Walter, A. ., Jones, T. ., Huang, E. ., & Davis, R. . A novel risk classification system for 30-day mortality in children undergoing surgery. PloS One, 13(1), e0191176. https://doi.org/10.1371/journal.pone.0191176 (Original work published 2018)