Lejk, M. (2002). An introduction to systems analysis techniquesMark Lejk, David Deeks. Addison-Wesley.
Lua i Stíl Chicago (17ú heag.)Lejk, Mark. An Introduction to Systems Analysis TechniquesMark Lejk, David Deeks. Addison-Wesley, 2002.
Lua MLA (8ú heag.)Lejk, Mark. An Introduction to Systems Analysis TechniquesMark Lejk, David Deeks. Addison-Wesley, 2002.
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