37167
" Surface forces " or " contact forces " , expressed as force per unit area , can act either on the bounding surface of the body , as a result of mechanical contact with other bodies , or on imaginary internal surfaces that bound portions of the body , as a result of the mechanical interaction between the parts of the body to either side of the surface ( Euler-Cauchy 's stress principle ) .
 Euler-Cauchy
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Euler-Cauchy