https://wol.iza.org/articles/cash-wage-payments-in-transition-economies-consequences-of-envelope-wages/v2/references
World of Labour - Cash wage payments in transition economies: Consequences of envelope wages
world of labourwage paymentsenvelope wagescashtransition
https://pure.urosario.edu.co/en/publications/detecting-envelope-wages-with-e-billing-information/
Detecting envelope wages with e-billing information - Universidad del Rosario
universidad del rosarioenvelope wagesbilling informationdetecting
https://www.ela.europa.eu/ka/taxonomy/term/223
Envelope wages | European Labour Authority
Often used in the context of under-declared employment, an envelope wage is a cash-in-hand wage paid by a formal employer to a formal employee in addition to...
envelope wageseuropeanlabourauthority