Primer

The colorful primer by Redozubov.
The experimental verification of Redozubov's method and primer fully confirmed the author's hypothesis about the necessity of thorough practical study by children of the basic speech sounds and their graphic representation, as well as the correctness... of the arrangement of sound and syllable difficulties in the primer. Clarity in knowledge related to the study of sounds, practical study of each sound separately and in combination with others made the process of learning to read an act of conscious assimilation by students of the main features of oral and written speech.
The system of primers from the 1950s is a natural continuation and completion of the direction initiated by Ushinsky. The changes made to it corresponded to modern data from linguistics, psychology, and pedagogy.