Exploring the practice of making informal payments in the health sector : some lessons from GreeceHorodnic, Adrian; Williams, Colin; Polese, Abel; Zait, Adriana; Oprea, LiviuThe informal economy in global perspective : varieties of governance2017 / p. 157-172 https://doi.org/10.1007/978-3-319-40931-3_9

Introduction : informal economies as varieties of governancePolese, Abel; Williams, Colin; Horodnic, Ioana; Bejakovic, PredragThe informal economy in global perspective : varieties of governance2017 / p. 1-14 https://doi.org/10.1007/978-3-319-40931-3_1

The informal economy in global perspective : varieties of governance2017 http://dx.doi.org/10.1007/978-3-319-40931-3