This is a specific topic. "Perks at work G4S" likely refers to employee benefits, non-monetary incentives, or workplace "perks" offered by the global security company (now part of Allied Universal after its 2021 acquisition).
Since G4S is a large, operationally heavy employer (security officers, cash handling, facility management), academic or industry papers on this topic would fall under , employee retention in blue-collar sectors , or total rewards in service industries .