research gap in introduction

53:33

5:02

1:38:42

23:09

7:58

51:43

7:53

17:17

1:36

2:58

2:58

کوتاه

3:14

14:14

16:39

2:31

7:04

2:00

6:53

5:57

7:42

11:32

13:49

1:52

5:03

1:08:16

11:46

23:52

4:38

4:13

40:10

31:09

25:12

3:14

2:50

8:18

14:05

6:48

کوتاه

7:12