Clausen, R. R., Christopher, T., Detrick, A., & Detrick, L. (2014). Essential perennials: The complete reference to 2700 perennials for the home garden (First edition.). Timber Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रClausen, Ruth Rogers, Thomas Christopher, Alan Detrick, और Linda Detrick. Essential Perennials: The Complete Reference to 2700 Perennials for the Home Garden. First edition. Portland: Timber Press, 2014.
एमएलए (8वां संस्करण) प्रशस्ति पत्रClausen, Ruth Rogers, et al. Essential Perennials: The Complete Reference to 2700 Perennials for the Home Garden. First edition. Timber Press, 2014.
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