The terminology is defined and illustrated in Section 1. A little historical background not very familiar to statisticians is sketched in Section 2. In Section 3 some difficulties about the formulation of random interactions are discussed. Section 4 deals with models reflecting a randomization in the experiment to assign the treatment combinations to finite populations of experimental units.
Henry Scheffe. "Alternative Models for the Analysis of Variance." Ann. Math. Statist. 27 (2) 251 - 271, June, 1956. https://doi.org/10.1214/aoms/1177728258