 Complete the following phrase:  On September 11, the Brigade withdrew towards Zambrów, next day it joined forces with Suwalska Cavalry Brigade, creating the so-called Group of General Zygmunt Podhorski: Zaza Cavalry Division Zaza after Zygmunt. Depleted in continuous fighting, it headed eastwards to Białowieża, reaching the Białowieża Forest on September 16. After the 