Harrison, Harry (2009). Toy Shop and Two Others. Wildside Press LLC. стр. 27. ISBN978-1-4344-5896-4. Приступљено 2011-10-14. „The applied study of the interaction of individuals in a culture, the interaction of the group generated by these individuals, the equations derived therefrom, and the application of these equations to control one or more factors of this same culture”