Table: czechoslovak_badminton_champs
Columns: year
men_s_singles
women_s_singles
men_s_doubles
women_s_doubles
mixed_doubles

Question: Which men's singles has a women's singles of marketa koudelková as well as a Men's doubles of jan lanik / pavel weigner??
SQL: SELECT "men_s_singles" FROM czechoslovak_badminton_champs WHERE "women_s_singles" = 'marketa koudelková' AND "men_s_doubles" = 'jan lanik / pavel weigner'

Question: Which men's singles had a women's doubles team of irena ferencová / yweta trminková?
SQL: SELECT "men_s_singles" FROM czechoslovak_badminton_champs WHERE "women_s_doubles" = 'irena ferencová / yweta trminková'

Question: What is the mean year when the women's doubles team was helena turcinková / buresová?
SQL: SELECT AVG("year") FROM czechoslovak_badminton_champs WHERE "women_s_doubles" = 'helena turcinková / buresová'