What is Belgrade Cooperative?

Legal Definition
Belgrade Cooperative (Serbian: Београдска задруга / Beogradska zadruga) is a cooperative bank founded in 1882 to promote savings and support small enterprises, craftspeople and the poor of Belgrade. Member-shareholders have been paying membership in amount of one Serbian Dinar per week. That is the way for cooperative to become a public savings bank. Luka Ćelović was the first president of cooperative, also a first Serbian insurance group.
-- Wikipedia