1. Using metrics to evaluate software system maintainability
2. Managing application program maintenance expenditures
3. Lientz, B.P., and Swanson, E.B.: ‘Software maintenance management: a study of the maintenance of computer application software in 487 data processing organizations’, (Addison-Wesley 1980)
4. Fowler, M.: ‘Refactoring: improving the design of existing programs’, (Addison-Wesley 1999)
5. Arnold, R.S.: ‘An introduction to software restructuring’, Tutorial on Software Restructuring, (IEEE 1986)