1. Normal blood flow and abnormal flow;Gumley,1987
2. Free flap surgery: the second decade;Khouri;Clin Plast Surg,1992
3. Head and neck cancer: the problem;Blair;Clin Plast Surg,1994
4. Calculating confidence intervals for relative risks, odds ratios, and standardised ratios and rates;Morris,1989
5. SPSS for Windows advanced statistics release 6.0.;Norusis,1993