Pakistan, June 21 -- Chairman of Pakistan Peoples Party (PPP) Bilawal Bhutto Zardari has paid rich tribute to Shaheed Mohtarma Benazir Bhutto on her 73rd birth anniversary, describing her as "Chaaron Soboon Ki Zanjeer" the enduring symbol of a united, democratic and progressive Pakistan. He said that her vision of a strong federation, empowered federating units, constitutional rule, and a society founded on dignity, equality, and opportunity for all continues to guide the PPP. He added that Shaheed Mohtarma Benazir Bhutto's legacy remains a beacon for a Pakistan that is secure in its defence, unwavering in the protection of its people's rights and steadfast in its support for the just struggle of the people of Jammu and Kashmir. The Chair...