Fitch, C., & Young, M. (2021). Subterranea: Journey into the depths of the Earth's most extraordinary underground spaces. Timber Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रFitch, Chris, और Matthew Young. Subterranea: Journey into the Depths of the Earth's Most Extraordinary Underground Spaces. Portland, Oregon: Timber Press, 2021.
एमएलए (8वां संस्करण) प्रशस्ति पत्रFitch, Chris, और Matthew Young. Subterranea: Journey into the Depths of the Earth's Most Extraordinary Underground Spaces. Timber Press, 2021.
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