“…Of the studies included in this review, 3 studies were written in Persian [ 17 , 18 , 19 ]. Contact with the authors, requesting the data, was necessary for 7 studies [ 17 , 18 , 20 , 21 , 22 , 23 , 24 ]. Of these studies, only 1 returned data [ 23 ] and two other studies [ 20 , 22 ] approximate data were used.…”