Slope

Bu kavram başka kaynaklarda da geçiyor

• A Dictionary of Military Terms (1918)
• Hawkins' Electrical Dictionary (1915)
• The Slang Dictionary Etymological Historical and Anecdotal (1913)
• Chamber's Twientieth Century Dictionary (1908)
• Phrases and Names Their Origins and Meanings (1896)
• Webster's Practical Dictionary- A Practical Dictionary of the Englih Language (1884)
• A Military Dictionary (1810)
• Centering-slope — A Dictionary of Military Terms (1918)
• Counter-slope — A Dictionary of Military Terms (1918)