Perrin, R. (1971). Focus the future: An introduction to long range corporate planning. Management.
शिकागो स्टाइल उद्धरणPerrin, Robert. Focus the Future: An Introduction to Long Range Corporate Planning. London: Management, 1971.
एमएलए उद्धरणPerrin, Robert. Focus the Future: An Introduction to Long Range Corporate Planning. Management, 1971.
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