Not a DOI

The resolution service at https://doi.org resolves DOIs. You have attempted to resolve core/services/aop-cambridge-core/content/view/A890CFF17F65C81B03EEA929A23C5F2E/S1368980012005447a.pdf/identifying-whole-grain-foods-a-comparison-of-different-approaches-for-selecting-more-healthful-whole-grain-products.pdf, which is not a DOI.

core/services/aop-cambridge-core/content/view/A890CFF17F65C81B03EEA929A23C5F2E/S1368980012005447a.pdf/identifying-whole-grain-foods-a-comparison-of-different-approaches-for-selecting-more-healthful-whole-grain-products.pdf may be a Handle (DOIs are a special sort of Handle). If core/services/aop-cambridge-core/content/view/A890CFF17F65C81B03EEA929A23C5F2E/S1368980012005447a.pdf/identifying-whole-grain-foods-a-comparison-of-different-approaches-for-selecting-more-healthful-whole-grain-products.pdf is a valid Handle you should be able to resolve it at https://hdl.handle.net.