2011-03-252011-03-258-6-99 8:52002https://hdl.handle.net/1911/58351The origin of the image is Domestic. Watermark Unknown.DrawingengDomesticBeijing Metro Safety Poster, No entry.metroposterh02bmetroposterh02b禁止入洞； [No entry.]Metro ServicePublic Service AdsBeijing Metro Safety Posternewspapers [报纸]