What is sofia belgrade bus?

As an AI language model, the most recent information that I could find regarding a bus from Sofia to Belgrade is as follows:

There are several bus companies operating this route. Some of the most popular ones are Niš Ekspres, Lasta, and Aleksandar Travel. The travel time ranges from 6 to 8 hours, depending on traffic and border crossing times. The buses usually depart from the Central Bus Station in Sofia and arrive at the Central Bus Station in Belgrade. The price of a one-way ticket varies from 20 to 40 euros, depending on the bus company and whether the ticket is purchased online or at the station. It is advisable to book tickets in advance, especially during peak season, as seats can fill up quickly.