This paper provides a method of decomposing a subclass of ETOL languages into deterministic ETOL languages. This allows one to use every known example of a language which is not a deterministic ETOL language to produce languages which are not ETOL languages.
Ehrenfeucht, Andrzej and Rozenberg, Grzegorz, "On Decomposing Some ETOL Languages Into Deterministic ETOL Languages ; CU-CS-045-74" (1974). Computer Science Technical Reports. 44.