Which women's doubles happened after 1987 and a women's single of astrid van der knaap?
CREATE TABLE table_80315 (
    "Year" real,
    "Men's singles" text,
    "Women's singles" text,
    "Men's doubles" text,
    "Women's doubles" text,
    "Mixed doubles" text
)
SELECT "Women's doubles" FROM table_80315 WHERE "Year" > '1987' AND "Women's singles" = 'astrid van der knaap'
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: Which women's doubles happened after 1987 and a women's single of astrid van der knaap? ### Input: CREATE TABLE table_80315 (
    "Year" real,
    "Men's singles" text,
    "Women's singles" text,
    "Men's doubles" text,
    "Women's doubles" text,
    "Mixed doubles" text
) ### Response: SELECT "Women's doubles" FROM table_80315 WHERE "Year" > '1987' AND "Women's singles" = 'astrid van der knaap'