Maintainers for libgtk-3-0 are Debian GNOME Maintainers <[email protected]>.
You may want to refer to the following packages that are part of the same source: gir1.2-gtk-3.0, gtk-3-examples, libgail-3-0, libgail-3-0t64, libgail-3-dev, libgail-3-doc, libgtk-3-0t64, libgtk-3-bin, libgtk-3-common, libgtk-3-dev, libgtk-3-doc.
You might like to refer to the libgtk-3-0 package page, to the Package Tracking System, or to the source package src:gtk+3.0's bug page.
If you find a bug not listed here, please report it.