@misc{indiciaeb0fd5010bbb3,
  title = {Rheumatoid factor in Nigerian sera.},
  author = {B M Greenwood and A S Muller and H A Valkenburg},
  year = {1971},
  url = {https://pubmed.ncbi.nlm.nih.gov/4936803/},
  note = {Source identifier: 4936803}
}