Name the period with matches of 0 0 of portugal
CREATE TABLE table_67942 (
    "Country" text,
    "Player name" text,
    "Period" text,
    "Position" text,
    "Matches" text,
    "Goals" text
)
SELECT "Period" FROM table_67942 WHERE "Matches" = '0 0' AND "Country" = 'portugal'
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: Name the period with matches of 0 0 of portugal ### Input: CREATE TABLE table_67942 (
    "Country" text,
    "Player name" text,
    "Period" text,
    "Position" text,
    "Matches" text,
    "Goals" text
) ### Response: SELECT "Period" FROM table_67942 WHERE "Matches" = '0 0' AND "Country" = 'portugal'