CREATE TABLE "past_winners" (
  "year" real,
  "mens_singles" text,
  "womens_singles" text,
  "mens_doubles" text,
  "womens_doubles" text,
  "mixed_doubles" text
);

Question: Name the womens singles for  raina tzvetkova petya nedelcheva
SQL: SELECT "womens_singles" FROM "past_winners" WHERE "womens_doubles"='Raina Tzvetkova Petya Nedelcheva';

Question: Name the number of years for womens doubles being  diana koleva emilia dimitrova and  jeliazko valkov
SQL: SELECT COUNT("year") FROM "past_winners" WHERE "womens_doubles"='Diana Koleva Emilia Dimitrova' AND "mens_singles"='Jeliazko Valkov';

Question: Name the mens singles for  jeliazko valkov dobrinka peneva
SQL: SELECT "mens_singles" FROM "past_winners" WHERE "mixed_doubles"='Jeliazko Valkov Dobrinka Peneva';

Question: Name the mens singles for 1989
SQL: SELECT "mens_singles" FROM "past_winners" WHERE "year"=1989;

Question: Name the year for victoria hristova neli nedialkova
SQL: SELECT "year" FROM "past_winners" WHERE "womens_doubles"='Victoria Hristova Neli Nedialkova';

Question: Name the year for womens doubles being raina tzvetkova emilia dimitrova
SQL: SELECT "year" FROM "past_winners" WHERE "womens_doubles"='Raina Tzvetkova Emilia Dimitrova';