General information:      https://beograd.rs/en/   
Tourist Organization of Belgrade:        https://tob.rs/en
History:      https://beograd.rs/en/discover-belgrade/201024-history/ 
Culture and Art:     https://beograd.rs/en/discover-belgrade/201038-culture-and-art/
Tourism (Useful information, Where to stay, Restaurants, Belgrade sightseeing tours):     https://beograd.rs/en/discover-belgrade/201177-tourism/ 
Belgrade hotels:
https://tripadvisor.com/Hotels-g294472-Belgrade-Hotels.html