A Career Grand Slam is a rare feat in tennis.
Steffi Graf Turns 50: The Numbers Behind One Of The Most Successful Tennis Players In History - UBITENNIS
Novak Djokovic advances to US Open semi-finals with win over Matteo Berrettini as Grand Slam beckons - ABC News
4 players who have won the Triple Career Grand Slam, ft. Steffi Graf, Novak Djokovic
Can you name any tennis players who have won multiple grand slams but never won at Wimbledon? Why do you think that is so for them specifically? - Quora
This day, that year: Graf became the only player to win a 'Calendar Golden Slam' - India Today
Novak Djokovic - Wikipedia
Steffi Graf - Wikipedia
Greatest U.S. Men's Tennis Players of All Time
Calendar Grand Slam: Who's Previously Attempted Tennis' Toughest Task
4 players who have won the Triple Career Grand Slam, ft. Steffi Graf, Novak Djokovic