Zombie research haunts academic literature long after its supposed demise

a retracted article is not deleted? how do people keep acquiring and citing it if it's retracted?

Shame it's behind a paywall.

Obviously directly derived works or studies that replicate results are probably suitable for withdrawl too under the same criteria. I wonder how many published papers on average should be withdrawn when events such as this happen. I suppose its related to impact assessments but I wonder how that varies from field to field.