Explicit Constructions of Ramanujan Complexes of Type $\tilde{A}_d$
  In this paper we present for every $d \geq 2$ and every local field $F$ of positive characteristic, explicit constructions of Ramanujan complexes which are quotients of the Bruhat-Tits building $\B_d(F)$ associated with $\operatorname{PGL}_d(F)$. 
Alex Lubotzky, Beth Samuels, Uzi Vishne