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Palveluiden tuottavuus: Kilpailu ja teknologiska muuttavat rakenteita
Mankinen, Reijo, (2002)
Conceptualizing productivity in services
Ojasalo, Katri, (1999)
Service productivity : toward a conceptualisation of the transformation of inputs into customer value in services
Grönroos, Christian, (2000)
International comparisons of real product and purchasing power
Kravis, Irving B., (1978)
World product and income : international comparisons of real gross product
Kravis, Irving B., (1982)