how can i drive the linear state space model of this ackerman steering model

i have an ackerman steering model like so :

    x_t = x_t_1 + v * cos(theta) * dt
y_t = y_t_1 + v * sin(theta) * dt
theta_t  = theta_t_1 + v/L * tan(phi) * dt


what i'm looking for is to derive a linear state space representation:  x_new = A*x_old+B*u given that the controls in this case are  v and phi