Complex sentence: Early research of bilingual lexical access was generated from the theories of unilingual lexical access, which were more like verbal description without precise specification of how these systems of lexical accesses would work, for example, the theory of serial search models and parallel access models.
Split into simpler sentences: Early research of bilingual lexical access was generated from the theories of unilingual lexical access. For example, the theory of serial search models and parallel access models.