Setting a custom Gtk theme for specific applications | urukrama's weblog
Human Compact Themes (for Ubuntu 8.10)
11 Best GTK Themes for Ubuntu - OMG! Ubuntu
Install Clearlooks-flat-compact GTK theme on Ubuntu 12.10/12.04/11.10/Mint - NoobsLab | Eye on Digital World
Toffee-gtk-theme - Eyecandy for your XFCE-Desktop - xfce-look.org
6 Best Ubuntu themes which works! - The Linux User
Some GTK3 programs do not react to themes at all / Desktop / Xfce Forums
Pop-compact variants: GNOME Top bar does not shrink, only the fonts shrink · Issue #51 · pop-os/gtk-theme · GitHub
Gtk / gnome-shell Theme Editing - Customization - Zorin Forum
Materia Theme - A Material Design Theme for GNOME/GTK+
7 Great-Looking Gnome Shell Themes - Make Tech Easier
Install GNOME Themes - Script To Install Over 40 Popular Gtk Themes - Linux Uprising Blog
How to Install Themes in Ubuntu Linux
Orchis Is A Cool GTK / GNOME Theme With Rounded Elements - Linux Uprising Blog
xfce - GTK theme doesn't works on every window - Super User
7 Great-Looking Gnome Shell Themes - Make Tech Easier
11 Best GTK Themes for Ubuntu - OMG! Ubuntu
Clearlooks Compact - Gnome-look.org
Orchis gtk theme - Gnome-look.org
GitHub - vinceliuice/Canta-theme: Canta is a flat Material Design theme for GTK 3, GTK 2 and Gnome-Shell which supports GTK 3 and GTK 2 based desktop environments like Gnome, Unity, Budgie, Pantheon,