Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Date | Venue | Opponents | Score | Competition | Scotland scorer(s) |
| --- | --- | --- | --- | --- | --- |
| 21 October 1950 | Ninian Park, Cardiff (A) | Wales | 3–1 | BHC | Lawrie Reilly (2), Billy Liddell |
| 1 November 1950 | Hampden Park, Glasgow (H) | Northern Ireland | 6–1 | BHC | Billy Steel (4), John McPhail (2) |
| 13 December 1950 | Hampden Park, Glasgow (H) | Austria | 0–1 | Friendly |  |
| 14 April 1951 | Wembley Stadium, London (A) | England | 3–2 | BHC | Bobby Johnstone, Lawrie Reilly, Billy Liddell |
| 12 May 1951 | Hampden Park, Glasgow (H) | Denmark | 3–1 | Friendly | Billy Steel, Lawrie Reilly, Robert Mitchell |
| 16 May 1951 | Hampden Park, Glasgow (H) | France | 1–0 | Friendly | Lawrie Reilly |
| 20 May 1951 | Heysel Stadium, Brussels (A) | Belgium | 5–0 | Friendly | George Hamilton (3), Jimmy Mason, Willie Waddell |
| 27 May 1951 | Prater Stadium, Vienna (A) | Austria | 0–4 | Friendly |  |
Question:
in which two games did scotland not score a goal?
Answer:
13 December 1950, 27 May 1951