Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_38 (isbn_uk VARCHAR, author VARCHAR, isbn_us VARCHAR)
### Question:
What is ISBN UK, when Author is "Dave Martin", and when ISBN US is "N/A"?
### Answer:
SELECT isbn_uk FROM table_name_38 WHERE author = "dave martin" AND isbn_us = "n/a"