Rule 17: Compound plurals containing a possessive

Keep the existing possessive term singular and make the second noun possessive as well

Examples

driver's licenses

renewal dates

nurse practitioners

Rule 18: Individual possession, two or more individuals

Show possession after each name when possession is not joint

Examples

Dr. Green's and Dr. White's conclusions difered.

Dr. Botham's and Dr. Windfield's ideas vary.

Dr. Rodney's and Dr. Davis' reports disagree.

Rule 19: Joint possession

Show possession only after the final name when possession is common to two or more individuals.

Examples

Doctors Smith and Brown's conclusion was...

Patients Anne and Samantha's blood group was...

Nurses Cameron and Jennifer's attended the...