First Among Equals: World No. 1 Record Breakers & Shakers | ATP Tour | Tennis
Alcaraz, Ruud to play for world No. 1 ranking in 2022 US Open men's singles final - Official Site of the 2023 US Open Tennis Championships - A USTA Event
Shintaro Mochizuki becomes world No. 1 for juniors - The Japan Times
WTA Rankings: Iga Swiatek Becomes New World Number One
Chart: Roger Federer Crowned Oldest No. 1 in Tennis at Age 36 | Statista
Tennis world number ones in pictures: Here is every man to hold top spot since computer rankings were introduced | Novak Djokovic record, Roger Federer, Rafael Nadal, Daniil Medvedev, Carlos Alcaraz
ATP Rankings 2019: Rafael Nadal No.1 men's player after overtaking Novak Djokovic | London Evening Standard | Evening Standard
Rafael Nadal: How can Roger Federer regain world No 1 spot without playing? | Tennis | Sport | Express.co.uk