Table: doctor_who_merch
Columns: title
author
isbn_uk
isbn_us
tv_companions_featured

Question: What is ISBN UK, when Author is "Dave Martin", and when ISBN US is "N/A"?
SQL: SELECT "isbn_uk" FROM doctor_who_merch WHERE "author" = 'dave martin' AND "isbn_us" = 'n/a'

Question: What is ISBN US, when Title is "Crisis In Space"?
SQL: SELECT "isbn_us" FROM doctor_who_merch WHERE "title" = 'crisis in space'

Question: What is Author, when TV Companions Featured is "Peri Brown", and when Title is "Race Against Time"?
SQL: SELECT "author" FROM doctor_who_merch WHERE "tv_companions_featured" = 'peri brown' AND "title" = 'race against time'

Question: What is Title, when TV Companions Featured is "K-9"?
SQL: SELECT "title" FROM doctor_who_merch WHERE "tv_companions_featured" = 'k-9'

Question: What is ISBN US, when Title is "Mission To Venus"?
SQL: SELECT "isbn_us" FROM doctor_who_merch WHERE "title" = 'mission to venus'

Question: What is TV Companions Featured, when Author is "William Emms"?
SQL: SELECT "tv_companions_featured" FROM doctor_who_merch WHERE "author" = 'william emms'