Nonlinear coherent states (CSs) and their {\it dual families} were introduced
recently. In this paper we want to obtain their superposition and investigate
their non-classical properties such as antibunching effect, quadrature
squeezing and amplitude squared squeezing. For this purpose two types of
superposition are considered. In the first type we neglect the normalization
factors of the two components of the dual pair, superpose them and then we
normalize the obtained states, while in the second type we superpose the two
normalized components and then again normalize the resultant states. As a
physical realization, the formalism will then be applied to a special physical
system with known nonlinearity function, i.e., Hydrogen-like spectrum. We
continue with the (first type of) superposition of the dual pair of
Gazeau-Klauder coherent states (GKCSs) as temporally stable CSs. An application
of the proposal will be given by employing the P\"oschl-Teller potential
system. The numerical results are presented and discussed in detail, showing
the effects of this special quantum interference.Comment: 19 pages, 18 figures, Accpeted for Publication in Optics
Communications, 201