Combination
Bulgaria 1970 / Single stamp (issued February 20th) / mint condition /
Michel #1981 / Yvert #1760
+
Bulgaria 1970 / Set of 4 stamps (issued June 20th) / mint condition /
Michel #2013-16 / Yvert #1786-89
+
Bulgaria 1970 / Mini-sheet (issued June 20th) imperf. / mint condition /
Michel #Block 27 / Yvert #BF29