Answer: sgs

AnswerCrossword Clue
SGSGibson guitars for Eric Clapton, Angus Young, and others
SGSKoop and Satcher (abbr.)
SGSC. Everett Koop et al.: Abbr.
SGSKoop and Satcher: Abbr.
SGSLaw officers: Abbr.
SGSCertain doctors: Abbr.
SGSTitles for Thant and Lie: Abbr.
SGSCertain medics: Abbr.
SGSHospital V.I.P.'s
SGSBan Ki-moon and others: Abbr.
SGSClassic Gibson guitars
SGSEnvironmental prefix
SGSKoop and Elders, briefly