“…By giving specific values to α , β , λ , p , b , and δ in 𝒱𝒟 p λ ( δ , b , α , β ), we obtain many important subclasses studied by various authors in earlier papers; see for details [ 3 – 6 ]; we list some of them as follows: - 𝒱𝒟 1 λ (0,2, 0,0) ≡ 𝒮 λ * and 𝒱𝒟 1 λ (1,1, 0,0) ≡ 𝒦 λ , studied by Spacek [ 7 ] and Robertson [ 8 ], respectively; for the advancement work see [ 9 – 11 ];
- 𝒱𝒟 1 0 (0,2, α , β ) ≡ 𝒮𝒟 ( α , β ) and 𝒱𝒟 1 0 (1,1, α , β ) ≡ 𝒦𝒟 ( α , β ), studied by both Owa et al and Shams et al [ 12 , 13 ];
- 𝒱𝒟 1 λ (0,2, 1,0) ≡ 𝒰𝒮𝒫 ( λ ) and 𝒱𝒟 1 λ (1,1, 1,0) ≡ 𝒰𝒞𝒮𝒫 ( λ ), introduced by Ravichandran et al [ 14 ];
- 𝒱𝒟 1 0 ( δ , b , α , β ) ≡ 𝒱𝒟 ( δ , b , α , β ), considered by Latha [ 15 ];
- 𝒱𝒟 1 0 (0,2, 0, β ) ≡ 𝒮 *( β ) and 𝒱𝒟 1 0 (1,1, 0, β ) ≡ 𝒦 ( β ), the well-known classes of starlike and convex functions of order β .
From the above special cases we note that this class provides a continuous passage from the class of starlike functions to the class of convex functions.…”