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- Language: English
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- Author: Robert W. Christopherson&Ginger H. Birkeland
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- Author: Robert W. Christopherson, Ginger Birkeland
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- Year: 2017

- Author: Robert W. Christopherson Ginger H. Birkeland Philip Thomas Giles Mary-Louise Byrne
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- Year: 2015

- Author: Robert W Christopherson
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- Year: 2013

- Author: Robert W. Christopherson
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- Year: 2011

- Author: Robert W. Christopherson
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- Year: 2004