-
41
-
42
-
43
-
44
-
45
-
46
-
47
-
48
-
49
-
50Published 1982“…Bulg. acad. of sciences…”
Book -
51
-
52
-
53Published 1983“…Ed. Acad. RSR…”
Book -
54
-
55
-
56Published 1986“…Ed. Acad. RSR…”
Book -
57
-
58Published 1987“…Ed. Acad. RSR…”
Book -
59Published 1987“…Ed. Acad. RSR…”
Book -
60Published 1987“…Ed. Acad. RSR…”
Book