
1) Alphabet trio 2) Alphabetic trio 3) NR connection 4) Trio after N
Found on
https://www.crosswordclues.com/clue/opq

The Occupational Personality Questionnaires, OPQ or OPQ32, are widely used occupational personality questionnaires. The authors were Saville et al., including Roger Holdsworth, Gill Nyfield, Lisa Cramp and Bill Mabey, and they were launched by Saville and Holdsworth Ltd. in 1984. The series included the first commercially available Big Five instru...
Found on
http://en.wikipedia.org/wiki/OPQ
No exact match found.