The unit group of some fields of the form Q(√2, √p, √q, √-l)

Let p and q be two different prime integers such that p≡ q≡38 with $(p/q)=1$, and l a positive odd square-free integer relatively prime to p and q. In this paper we investigate the unit groups of number fields L=Q(√2, √p, √q, √-l).