title: Three giants tighten their grip.
authors.forename: Peng
authors.initials: P
authors.lastname: Tian
mesh_terms: D000162:Acoustics; D000068476:Beijing; D002621:Chemistry / Q000706:statistics & numerical data; D002681:China; D002947:Cities / Q000191:economics / Q000706:statistics & numerical data*; D012106:Research / Q000191:economics / Q000706:statistics & numerical data*