"Archived copy"(PDF). cees.colorado.edu. Archived from the original(PDF) on 7 August 2011. Retrieved 12 January 2022.{{cite web}}: CS1 maint: archived copy as title (link)
"Archived copy"(PDF). cees.colorado.edu. Archived from the original(PDF) on 7 August 2011. Retrieved 12 January 2022.{{cite web}}: CS1 maint: archived copy as title (link)