3Howells AD, Roberts KR, Shanktin CW,et al. Restaurant employees ' perceptions of barriers to three food safety practices[J]. J Am Diet Assoc, 2008,108(8) ：1345-1349.
4Qiang Wang,Daizhi An, Liang Wen, et al. Food hygiene supervision during a major conference in Beijing:Deriptive analysis of impact on risk factors[J]. Food Control, 2012,28(2) : 279 285.
