DVD #4 in this series is the best, as it sticks to women-only sex, mainly among the students but with an adult lady or two thrown into the mix.
Of the dozen segments my favorite was selected from #18 in the Russian Institute series: "La Directrice". Ultra-busty (and fake but still fun to see) Clanddi Jinkcego plays the headmistress, having her way dominating one of her jail-bait charges in a stimulating lesbian scene. She's wisely called back in the final DVD, with guys added.