“…the BKP hierarchy and CKP hierarchy. About the BKP hierarchy, a lot of studies on additional symmetries have been done, such as additional symmetries of the BKP hierarchy [33], dispersionless BKP hierarchy [31,34], twocomponent BKP hierarchy [24] and its reduced hierarchies [20,21], supersymmetric BKP hierarchy [25] and so on. Dispersionless integrable systems [26] are very important in the study of all kinds of nonlinear sciences in physics, particularly in the application on the topological field theory [27] and matrix models [28,29].…”