A graph is said to be edge $\theta_0$-critical if for all $e \in E(G)$, $G-e$ is perfect.
"Every edge $\theta_0$-critical graph is $C_{2n+1}$, $n \geq 2$". This was proved in 1969 by E. Olaru.
Since this paper is not available online is there any alternate proof for this?