The X Window System This chapter describes the X Window system graphical user interface.
"Debian GNU/Linux: Guide to Installation and Usage"
John Goerzen and Ossama Othman
What is true of water and oil in this respect also holds good for the boundary or interface of any two liquids which do not mix.
"Liquid Drops and Globules, their Formation and Movements"
Chas. R. Darling
It then rises to the interface; breaks through, and mingles with the floating liquid, thereby losing its identity.
"Liquid Drops and Globules, their Formation and Movements"
Chas. R. Darling