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_14 (source VARCHAR, type VARCHAR, nat VARCHAR)
### Question:
WHAT IS THE SOURCE WITH A TYPE OF TRANSFER AND MEX?
### Answer:
SELECT source FROM table_name_14 WHERE type = "transfer" AND nat = "mex"