Kinsey's scale of heterosexual and homosexual responses
<span class="int-own-work" lang="en">Own work</span>
1948, 1953
<i><a href="https://en.wikipedia.org/wiki/Sexual_Behavior_in_the_Human_Female" class="extiw" title="en:Sexual Behavior in the Human Female">Sexual Behavior in the Human Female</a></i> (1953)