You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "when did 2 spaces after a period change?" whose answer is 1950.
Each document should contain about 30 words, and these documents should contain useful information.

Query: when did the rule of using one space instead of two spaces after a period change
Useful Output:

Doc 1: Microsoft Word will now flag two spaces after a period as an error, putting an end to the debate.
Doc 2: Microsoft Word has started marking double spaces between sentences as errors. Though the feature isn't yet universal, the company has begun trialing the change.
Doc 3: The first edition of AP Stylebook that recommends a single space after a period was published in 2009. The Chicago Manual of Style didn't
Doc 4: Apparently defying Betteridge's Law, the study claims to show that two spaces after a period are easier to read than one. On its face, this
Doc 5: There is no source for the single-space after a period rule (which during the nineteenth century was generally only found as a minority practice