[5] [5] KIM S J, HONG S. Chemical enhancement of footwear impressions in urine on the surface of tiles［J］. Analytical Science & Technology, 2019, 32(3): 113-119.

[6] [6] VIRKLER K, LEDNEV I K. Analysis of body fluids for forensic purposes: From laboratory testing to non-destructive rapid confirmatory identification at a crime scene［J］. Forensic Science International, 2009, 188(1/2/3): 1-17.

[8] [8] FARRUGIA K J, BANDEY H, BLEAY S, et al. Chemical enhancement of footwear impressions in urine on fabric［J］. Forensic Science International, 2012, 214(1/2/3): 67-81.

[9] [9] WANG X N, WU Y J, ZHANG T. Multi-layer feature based shoeprint verification algorithm for camera sensor images［J］. Sensors, 2019, 19(11): 2491.

[16] [16] VELLA J G, FARRUGIA N. Footwear impressions retrieval through textures and local features［M］//TAGAREV T, ATANASSOV K T, KHARCHENKO V, et al. Digital transformation, cyber security and resilience of modern societies. Cham: Springer, 2021: 343-360.