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Joe Kral: Scientific American: Volume 236, Issue 02
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Joe Kral: Scientific American: Volume 236, Issue 03
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Joe Kral: Scientific American: Volume 236, Issue 04
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Joe Kral: Scientific American: Volume 236, Issue 06
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Joe Kral: Scientific American: Volume 238, Issue 03
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Joe Kral: Scientific American: Volume 238, Issue 06
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Joe Kral: Scientific American: Volume 239, Issue 01
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Joe Kral: Scientific American: Volume 239, Issue 02
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Joe Kral: Scientific American: Volume 239, Issue 04
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Joe Kral: Scientific American: Volume 239, Issue 06
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Joe Kral: Scientific American: Volume 240, Issue 02
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Joe Kral: Scientific American: Volume 240, Issue 03