http://dcherukhin.i2p/research/research.htm
Ser. 1. 9(1): 84-94 (2002), in Russian [links: mathnet , Zbl 1009.68056 , ams ] Abstract: Let $f(x_1,\dots,x_n)$ and $g(x_1,\dots,x_m)$ be Boolean functions. A function
$$(f\otimes g)(x_1,\dots,x_nm)=
f\bigl(g(x_1,\dots,x_m),\dots,g(x_{(n-1)m+1},\dots,x_nm)\bigr)$$ is called a
repetition-free product of Boolean functions.