Not a DOI

The resolution service at https://doi.org resolves DOIs. You have attempted to resolve core/services/aop-cambridge-core/content/view/DCFF5347D39E15FB14831A163A039D44/S0007125000274679a.pdf/day-to-day-associations-between-subjective-sleep-and-affect-in-regard-to-future-depressionin-a-female-population-based-sample.pdf, which is not a DOI.

core/services/aop-cambridge-core/content/view/DCFF5347D39E15FB14831A163A039D44/S0007125000274679a.pdf/day-to-day-associations-between-subjective-sleep-and-affect-in-regard-to-future-depressionin-a-female-population-based-sample.pdf may be a Handle (DOIs are a special sort of Handle). If core/services/aop-cambridge-core/content/view/DCFF5347D39E15FB14831A163A039D44/S0007125000274679a.pdf/day-to-day-associations-between-subjective-sleep-and-affect-in-regard-to-future-depressionin-a-female-population-based-sample.pdf is a valid Handle you should be able to resolve it at https://hdl.handle.net.