2182-8458
2182-8458
S2182-84582020000400023
10.18089/tms.2020.160402
Bulgaria
30
12
2020
30
12
2020
16
4
23
34
[
2015
13
3
3
132-40
]
[
2000
31
4
4
453-64
]
[
2007
37
2
2
87-112
]
[
2014
7
2
2
75-80
]
[
2018
27
1
1
1-24
]
[
2013
12
2-3
2-3
122-37
]
[
2017
29
4
4
425-41
]
[
2006
48
7
7
518-31
]
[
2013
2
3
3
275-94
]
[
2012
26
2
2
246-61
]
[
2015
53
4
4
828-42
]
[
1982
4
1
1
33-50
]
[
2014
44
3
3
169-80
]
[
2017
26
2
2
125-37
]
[
2018
20
2
2
32-45
]
[
European Commission
2010
]
[
2019
66
Special issue
Special issue
73-89
]
[
2018
9
1
1
239-62
]
[
2015
45
4
4
247-54
]
[
2017
19
1
1
61-73
]
[
2014
]
[
2018
7
4
4
1-13
]
[
2018
24
1
1
45-67
]
[
2018
69
2
2
459-82
]
[
2010
92
4
4
347-63
]
[
2019
10
4
4
489-521
]
[
2011
24
2
2
141-56
]
[
2014
]
[
2018
27
3
3
295-318
]
[
2011
12
4
4
369-78
]
[
2011
126
12
12
381-90
]
[
2011
23
3-4
3-4
259-79
]
[
2012
879-84
]
[
2018
]
[
2013
284-302
]
[
2015
8
4
4
696-714
]
[
2001
22
545-64
]
[
2014
48-64
]
[
2018
58-75
]
[
2016
17
1
1
69-85
]
[
2009
28
3
3
241-51
]
[
2017
]
[
2014
145-59
]
[
2007
72-86
]
[
2019
8
2
2
56-74
]
[
2010
6
4
4
239-313
]
[
2011
41
2
2
103-20
]
[
2018
40
8
8
1043-65
]
[
2004
46
492-500
]
[
2000
42
6
6
356-65
]
[
2017
21
3
3
163-9
]
[
2018
31
7-8
7-8
611-27
]
[
2012
40
3
3
237-55
]
[
1991
3
1
1
33-48
]
[
2017
59
7-8
7-8
720-39
]
[
2015
17
38
38
358-69
]
[
2017
10
1
1
21-39
]
[
2017
25
September
September
85-98
]
[
2010
43
2
2
200-1
]
[
2018
24
1
1
290-314
]
[
2002
4
1
1
37-52
]
[
2019
22
1
1
177-88
]