Introduction
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PII: S1071-9091(07)00020-4
doi:10.1016/j.spen.2007.03.001
© 2007 Elsevier Inc. All rights reserved.
PII: S1071-9091(07)00020-4
doi:10.1016/j.spen.2007.03.001
© 2007 Elsevier Inc. All rights reserved.