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Cheng Y, Macera CA, Davis DR, Ainsworth BE, Troped PJ, Blair SN.Cheng Y, et al.J Clin Epidemiol. 2000 Mar 1;53(3):315-22. doi: 10.1016/s0895-4356(99)00168-7.J Clin Epidemiol. 2000.PMID: 10760643
Cheng Y, Macera CA, Davis DR, Blair SN.Cheng Y, et al.Br J Sports Med. 2000 Apr;34(2):116-21. doi: 10.1136/bjsm.34.2.116.Br J Sports Med. 2000.PMID: 10786867Free PMC article.
Cheng Y, Macera CA, Davis DR, Blair SN.Cheng Y, et al.West J Med. 2000 Aug;173(2):101-7. doi: 10.1136/ewjm.173.2.101.West J Med. 2000.PMID: 10924430Free PMC article.