[29]　因为它增加了头发表面和头皮之间的空间厚度：Jablonski interview.
[30]　人类似乎并没有信息素：‘Do Human Pheromones Actually Exist?', Science News, 7 March 2017.
[31] 次级毛发是为了展示之用：Bainbridge, Teenagers, pp. 44-45.
[32]　我们每个人一生会长出大约8米的头发：The Curious Cases of Rutherford and Fry, BBC Radio 4, 22 Aug. 2016.
[33]　该系统引入了“面部照片”(mugshot)的概念和做法：Cole, Suspect Identities, p. 49.
[34] 头一个确定指纹独特性：Smith, Body, p. 409.
[35] 它们有助于抓握：Linden, Touch, p. 37.