Specular Lighting Issue on Unlit Shader from graph shader

Hi everybody,

So, here i am trying to create some shader with this shader graph.
I did a Unlit shader who calculate Light direction, color for simulate shadow.

I succeed to calculate what seems to be a specular but it is to dependant from the view direction, making the white spot to change his shape as the camera move around the object.

I work with the 2019.2.14f1 version of Unity.

I’d like to rework the specular to make it more realistic in it behaviour

Specular highlights are supposed to be dependent on the view direction and light direction.