“…Twenty-four studies were conducted in America [ 17 , 18 , 22 , 39 , 43 , 50 , 51 , 52 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 65 , 67 , 71 , 73 , 77 , 78 , 81 ], 20 in Europe [ 12 , 27 , 38 , 42 , 44 , 45 , 46 , 47 , 48 , 49 , 53 , 54 , 64 , 66 , 68 , 69 , 70 , 72 , 79 , 80 ], 17 in Asia [ 19 , 20 , 23 , 24 , 29 , 30 , 32 , 33 , 34 , 35 , 36 , 37 , 40 , 41 ,…”