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_30011_2 (reference VARCHAR, type_and_usage VARCHAR)
### Question:
What is every reference for type and usage of Germanium small-signal RF transistor?
### Answer:
SELECT reference FROM table_30011_2 WHERE type_and_usage = "Germanium small-signal RF transistor"