Phi Sigma Alpha
Phi Sigma Alpha , commonly known as La Sigma , is a Puerto Rican fraternity originally established as the Sigma Delta Alpha Fraternity ( Sociedad de Amigos ) on October 22 , 1928 , at the University of Puerto Rico by 12 students and a professor . 
<triplet> Phi Sigma Alpha <subj> October 22, 1928 <obj> inception