“Do Authors Check Their References? A Survey of Accuracy of References in 3 Public Health Journals”, 1987-08-01 (; backlinks; similar):
We verified a random sample of 50 references in the May 1986 issue of each of 3 public health journals.
31% of the 150 references had citation errors, one out of 10 being a major error (reference not locatable). 30% of the references differed from authors’ use of them with half being a major error (cited paper not related to author’s contention).