"Love was the first investigator to present a successful approximation shell theory based on classical elasticity. To simplify the strain-displacement relationships and, consequently, the constitutive relations, Love [in this Treatise] introduced the following assumptions, known as the first approximations and commonly termed the Kirchoff-Love hypotheses..."
January 1, 1970
https://en.wikiquote.org/wiki/A_Treatise_on_the_Mathematical_Theory_of_Elasticity