readme: https://www.geogebra.org/m/cwcveget
  https://www.geogebra.org/m/b8dzxk6z
  https://www.geogebra.org/m/nqanttum
  https://www.geogebra.org/m/pd3g8a4u
  https://www.geogebra.org/m/jw8324jz
  https://www.geogebra.org/m/wjbpvz5q
  https://www.geogebra.org/m/qm3g3ma6
  https://www.geogebra.org/m/sdajgph8
  https://www.geogebra.org/m/e3ghhcbf
  https://www.geogebra.org/m/msne4bfm
  https://www.geogebra.org/m/nmcv2te5
  https://www.geogebra.org/m/hguqx6cn
  https://www.geogebra.org/m/jnyvpgqu
  https://www.geogebra.org/m/syctd97g
  https://www.geogebra.org/m/nq9erdby
  https://www.geogebra.org/m/au4har8c
  https://network.aza.org/network/members/profile?UserKey=811de229-7f08-4360-863c-ac04181ba9c0
  https://network.aza.org/network/members/profile?UserKey=31b495a0-36f7-4a50-ba3e-d76e3487278c
  https://network.aza.org/network/members/profile?UserKey=753c0ddd-bded-4b03-8c68-11dacdd1f676
  https://network.aza.org/network/members/profile?UserKey=db9d0a25-1615-4e39-b61f-ad68766095b3
  https://network.aza.org/network/members/profile?UserKey=59279f52-50cf-4686-9fb0-9ab613211ead
  https://network.aza.org/network/members/profile?UserKey=67b3ce20-cc3a-420f-8933-10796f301060
  https://network.aza.org/network/members/profile?UserKey=f5e610c3-6400-4429-b42b-97eeeeb284a9
  https://network.aza.org/network/members/profile?UserKey=ccda0739-f5f5-4ecc-a729-77c9a6825897
  https://network.aza.org/network/members/profile?UserKey=3983471f-cf43-4a4a-90d3-148040f92dd9
  https://network.aza.org/network/members/profile?UserKey=9f16d7a8-3502-4904-a99a-38362de78973
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  https://network.aza.org/network/members/profile?UserKey=178276d7-c64d-408e-af52-96d1ebd549fc