Where it comes from
Pokemon announces Sword/Shield 6m first week (Famitsu repost of TPC release) Famitsu (reprinting Pokemon Co. release) · 21 November 2019 Open the original ↗
The line in the source
全世界での600万本の初週販売本数は、Nintendo Switchソフトとして史上最速・最多となります。 (fastest and highest ever for a Switch title)