Sigma Paper No. 4: Management Control in Modern Government Administration: Some Comparative Practices (1996) Sigma Paper No. 19: Effects of European Union Accession: Part I Budgeting and Financial Control (1998) Sigma Paper No. 20: Effects of European Union Accession: Part II External Audit (1998) Sigma Paper No. 27: European Principles for Public Administration (1999) Sigma Paper No. 40: Central Public Procurement Structures and Capacity in Member States of the European Union (2007)