Lehtonen, R. (2004). Practical methods for design and analysis of complex surveys Risto Lehtonen, Ekki Pahkinnen. John Wiley.
Lua i Stíl Chicago (17ú heag.)Lehtonen, Risto. Practical Methods for Design and Analysis of Complex Surveys Risto Lehtonen, Ekki Pahkinnen. John Wiley, 2004.
Lua MLA (8ú heag.)Lehtonen, Risto. Practical Methods for Design and Analysis of Complex Surveys Risto Lehtonen, Ekki Pahkinnen. John Wiley, 2004.
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