@techreport{2004_spotcodes,
  author = {Eleanor Toye Scott and Anil Madhavapeddy and Richard Sharp and Dave Scott and Alan Blackwell and Eben Upton},
  doi = {10.48456/tr-609},
  institution = {University of Cambridge, Computer Laboratory},
  month = {dec},
  number = {UCAM-CL-TR-609},
  title = {Using camera-phones to interact with context-aware mobile services},
  url = {https://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-609.html},
  year = {2004}}