Where it comes from
Japanese-language article, 2019 Famitsu (reporting TPC release) · 21 November 2019 Open the original ↗
The line in the source
全世界で600万本の初週販売本数を突破 ... Nintendo Switchソフトとして史上最速・最多 (6m worldwide first week; fastest/most for a Switch title; 任天堂調べ)