Burj Khalifa
Burj Khalifa was designed by Adrian Smith , of Skidmore , Owings & Merrill , whose firm designed the Willis Tower and One World Trade Center . 
<triplet> Burj Khalifa <subj> Adrian Smith <obj> architect <subj> Skidmore, Owings & Merrill <obj> architect <triplet> Willis Tower <subj> Skidmore, Owings & Merrill <obj> architect <triplet> One World Trade Center <subj> Skidmore, Owings & Merrill <obj> architect