Borussia Dortmund's Mats Hummels losing sleep over transfer speculation | Borussia Dortmund | The Guardian
Mats Hummels - Wikipedia
Mats Hummels: Borussia Dortmund's £35 Million Investment Is Paying Dividends
Borussia Dortmund star Mats Hummels could join Manchester City, according to his father - Bitter and Blue
The Daily Bee: Mats Hummels Open to Contract Extension - Fear The Wall
Mats Hummels Is Borussia Dortmund Player Who Must Produce After Internationals | News, Scores, Highlights, Stats, and Rumors | Bleacher Report
I never thought I'd play in the Bundesliga' - World Cup winner Hummels reveals how he almost didn't make the grade | Goal.com Singapore
Manchester United transfer news: Mats Hummels 'tells team-mates' his Borussia Dortmund exit is on the verge of being sealed | The Independent | The Independent
Bundesliga: Nico Schlotterbeck wants Mats Hummels and Marco Reus to stay at Dortmund | PlanetSport
Borussia Dortmund defender Mats Hummels unsure of future at club | Football News | Sky Sports
Mats Hummels – The unsung hero of German football – Back Page Football