@misc{indiciae34224ae82014,
  title = {Further study of performance errors on Ravens progressive matrics (1938).},
  author = {C Sheppard and D Fiorentino and L Collins and S Merlis},
  year = {1969},
  doi = {10.1080/00223980.1969.10543078},
  url = {https://pubmed.ncbi.nlm.nih.gov/4388581/},
  note = {Source identifier: 4388581}
}