Question: Angelique Kerber and Hana Mandlíková are both what?

Context articles: 1988 Virginia Slims of Washington – Singles
2016 Angelique Kerber tennis season
2016 Australian Open – Women's Singles
Angelique Kerber career statistics
1988 Ariadne Classic – Doubles
1988 Ariadne Classic – Singles
Hana Mandlíková
Angelique Kerber
2017 US Open – Women's Singles
1988 Virginia Slims of California – Doubles

Hana Mandlíková was the defending champion but lost in the semifinals to Martina Navratilova.
The 2016 Angelique Kerber tennis season officially began on 5 January with the start of the 2016 Brisbane International.
 Kerber entered the season as the number 10 ranked player and the defending champion at four tournaments.
Serena Williams was the defending champion, and attempting for the second time to equal Steffi Graf's career record of 22 major singles titles.
 She lost in the final to Angelique Kerber, 4–6, 6–3, 4–6.
 Kerber became the first woman to win a singles major title after having saved a match point in the first round, which she did against Misaki Doi.
 She is also the first German of either sex to win a major since Graf at the 1999 French Open.
This is a list of the main career statistics of German professional tennis player, Angelique Kerber.
 To date, Kerber has won ten WTA singles titles including two grand slam singles titles at the 2016 Australian Open and 2016 US Open and at least one title on each playing surface (hard, clay and grass).
 She was also the runner-up at the 2016 Wimbledon Championships and a Silver medalist at the 2016 Rio de Janeiro Olympics.
 Kerber became the world No. 1 for the first time in her career on 12 September 2016.
Hana Mandlíková and Wendy Turnbull were the defending champions but they competed with different partners that year, Mandlíková with Jana Novotná and Turnbull with Elizabeth Smylie.
Hana Mandlíková was the defending champion but did not compete that year.
Hana Mandlíková (born 19 February 1962) is a former professional tennis player from Czechoslovakia who later obtained Australian citizenship.
 During her career, she won four Grand Slam singles titles: the 1980 Australian Open, 1981 French Open, 1985 US Open, and the 1987 Australian Open.
 She was also the runner-up at four Grand Slam singles events, including the Wimbledon finals of 1981 and 1986, and won one Grand Slam women's doubles title, the 1989 US Open with Martina Navratilova.
Angelique Kerber (] ; born 18 January 1988) is a German professional tennis player and former world No. 1.
 Having made her professional debut in 2003, Kerber rose to prominence upon reaching the semifinals of the 2011 US Open as the no. 92 ranked player in the world.
 She ascended to the top of the rankings on 12 September 2016, thus becoming the twenty-second and oldest player to achieve the number one ranking for the first time and the first new number one player since Victoria Azarenka in 2012.
Angelique Kerber was the defending champion, but lost in the first round to Naomi Osaka.
 This loss would cause Kerber to fall outside the top ten in the WTA rankings for the first time since 2015.
In the Doubles competition of the 1988 Virginia Slims of California tennis tournament, Hana Mandlíková and Wendy Turnbull were the defending champions but they competed with different partners: Mandlíková with Jana Novotná and Turnbull with Zina Garrison.