Why are Retracted journal articles still being cited?
There is evidence (Van der Vet & Nijveen 2016) that retracted journal articles continue to be cited after they are retracted. Reasons include carelessness on the part of the authors and publishers failing to clearly identify retracted journal articles. It may also stem from a lack of information associated with the source of the journal article. For example, papers shared or taken from personal collections where they are not identified as retracted or non-publisher versions of papers that are made available on the public web without the relevant Retraction information.
You are advised be to check the publisher’s website where you source the full text of a journal article from elsewhere. See also Searching for Retracted Journal Articles.