RecursiveS​ystematicc​onvolution​alEncoder

Can anyone give me a good example on how describe the generator matrix and feedback connections for a Recursive Sstematic convolutional code for rate 2/3.

For feedforward scenario, i can simply use trellis = poly2trellis([5 4],[23 35 0; 0 5 13]) But if I want to design a recursive one, how to provide the feedback connections

Any help is appreciated