What is every reference for the example of AF117?
CREATE TABLE table_31424 (
    "Prefix class" text,
    "Type and usage" text,
    "Example" text,
    "Equivalent" text,
    "Reference" text
)
SELECT "Reference" FROM table_31424 WHERE "Example" = 'AF117'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: What is every reference for the example of AF117? ### Input: CREATE TABLE table_31424 (
    "Prefix class" text,
    "Type and usage" text,
    "Example" text,
    "Equivalent" text,
    "Reference" text
) ### Response: SELECT "Reference" FROM table_31424 WHERE "Example" = 'AF117'