How to create a semi transparent plastic shader? I'd like to create a semi transparent plastic cycles material to match the material from this reference:




My current node setup 

 
First rendering 

Any suggestion or help on that topic, what's missing and what I should add to get that plastic material look is appreciated. Thanks.
There are elements of Refraction, Glossy, and Subsurface scattering in there so how about something like this :



This produces the following :



Vary the Mix factors, roughness and Subsurface scale to get the desired effect. Don't forget to have something in the scene to reflect/refract - eg, world environment texture and/or patterned surface, and suitable lighting, etc. Also, bevel any edges and ensure to add thickness.