Question: Who has won more Grand Slam doubles titles, Elizabeth Smylie or Vasek Pospisil?

full_context: Document 1: Łukasz Kubot: Łukasz Kubot (; born May 16, 1982) is a Polish professional tennis player. Kubot is a doubles specialist and won the 2014 Australian Open men's doubles title with Robert Lindstedt as well as the 2017 Wimbledon men's doubles title with Marcelo Melo. He has also had success in singles, achieving a career-high singles ranking of World No. 41 in April 2010 and reaching the quarterfinals of the 2013 Wimbledon Championships. In 2013 he was awarded the Gold Cross of Merit by Polish President Bronisław Komorowski.
Document 2: Margaret Court career statistics: This is a list of the main career statistics of Australian former tennis player Margaret Court. She won 64 Grand Slam events (24 singles, 19 doubles, 21 mixed doubles), which is a record for a male or female player. Her 24 Grand Slam singles titles and 21 in mixed doubles are also all-time records for both sexes. She achieved a career Grand Slam in singles, doubles, and mixed doubles. She is one of two women to have achieved "the" calendar year Grand Slam in singles in the Open Era (alongside Steffi Graf), and is the only woman to have achieved the mixed doubles Grand Slam, which she did twice.
Document 3: Vasek Pospisil: Vasek Pospisil (, ] ; born June 23, 1990) is a Canadian professional tennis player. He is the No. 3 male ranked player in Canada, after Milos Raonic and Denis Shapovalov. Pospisil has a career-high World singles ranking of 25, and No. 4 in doubles. As Canada's currently ranked No. 3 in singles and No. 3 in doubles, he is an important member of the Canada Davis Cup team. Along with partner Jack Sock, he won the 2014 Wimbledon Championships and the 2015 Indian Wells Masters men's doubles titles. He also reached the quarterfinals in singles at the 2015 Wimbledon Championships.
Document 4: Jean-Julien Rojer: Jean-Julien Rojer (] ; born 25 August 1981) is a Dutch professional tennis player from Curaçao. His highest ATP singles ranking is 218th, which he achieved on 15 August 2005. A doubles specialist, his career-high in doubles is World No. 3, which he reached in November 2015. His former doubles partners include Eric Butorac and Aisam-ul-Haq Qureshi. He currently plays with Horia Tecău of Romania, with whom he won the men's double titles in the 2015 Wimbledon and 2017 US Open championships. With Anna-Lena Grönefeld, he also won the mixed doubles' title at the 2014 French Open. He attended UCLA where he competed for the UCLA Bruins men's tennis team.
Document 5: Mate Pavić: Mate Pavić (born 4 July 1993) is a Croatian professional tennis player specialising in doubles. Mate won the 2016 US Open mixed doubles title in partnership with Laura Siegemund, and reached the 2017 Wimbledon Championships men's doubles finals partnering Oliver Marach.
Document 6: Virginia Wade: Sarah Virginia Wade, (born 10 July 1945) is a former professional tennis player from Great Britain. She won three Grand Slam singles championships and four Grand Slam doubles championships, and is the only British woman in history to have won titles at all four Grand Slam tournaments. She was ranked as high as No. 2 in the world in singles, and No. 1 in the world in doubles.
Document 7: Rennae Stubbs: Rennae Stubbs (born 26 March 1971) is an Australian retired tennis player. She was an Australian Institute of Sport scholarship holder. She has won four Grand Slam doubles titles and two Grand Slam mixed doubles titles. She was ranked world No.1 in doubles for three weeks in 2000. She represented Australia at four successive Summer Olympic Games: Atlanta 1996, Sydney 2000, Athens 2004, and Beijing 2008.
Document 8: 2016 China Open – Men's Doubles: Vasek Pospisil and Jack Sock were the defending champions, but Pospisil chose to play in Tokyo instead. Sock played alongside Bernard Tomic but lost in the final to Pablo Carreño Busta and Rafael Nadal, who won 6−7, 6−2, [10−8].
Document 9: 2015 Wimbledon Championships – Men's Doubles: Vasek Pospisil and Jack Sock were the defending champions, but lost in the third round to Jamie Murray and John Peers. Jean-Julien Rojer and Horia Tecău won the title by defeating Murray and Peers in the final by a score of 7–6, 6–4, 6–4.
Document 10: Félix Auger-Aliassime: Félix Auger-Aliassime (born August 8, 2000) is a Canadian professional tennis player. He reached a career high ATP singles ranking of No. 161 on September 18, 2017 and a career high ITF junior ranking of No. 2 on June 6, 2016. He is the youngest player ever to qualify and to win a main draw match on the ATP Challenger Tour. With his titles at the Open Sopra Steria de Lyon in June 2017 and the Copa Sevilla in September 2017, he became the seventh youngest player in history (16 years, 10 months) to win an ATP Challenger title and the second youngest to win multiple ATP Challenger titles. Auger-Aliassime won the 2016 US Open junior singles title and the 2015 US Open junior doubles title with compatriot Denis Shapovalov.
Document 11: Samantha Stosur career statistics: This is a list of the main career statistics of professional Australian tennis player, Samantha Stosur. To date, Stosur has won eight WTA singles titles including one Grand Slam singles title at the 2011 US Open. She was also the runner-up at the 2010 French Open and a semi-finalist at the 2010 and 2011 WTA Tour Championships. Stosur has also enjoyed a successful doubles career, in which she has held the World No. 1 ranking and won twenty-four WTA doubles titles including two grand slam women's doubles titles at the 2005 US Open and 2006 French Open and two year-ending championships at the 2005 and 2006 WTA Tour Championships.
Document 12: Evonne Goolagong career statistics: This is a list of the main career statistics of Australian former tennis player Evonne Goolagong. During her career, which lasted from 1967 to 1983, Goolagong won seven singles titles at a Grand Slam event and was a runner-up on 11 occasions. In addition she won five Grand Slam doubles titles, partnering Margaret Court, Peggy Michel and Helen Gourlay, as well as one mixed doubles title with Kim Warwick. In total she won 82 singles titles, 46 doubles titles and 4 mixed doubles titles. She achieved a No. 1 singles ranking for a two-week period in April–May 1976 although this was only officially recognized in 2007. She was a member of the Australian Federation Cup teams that won the cup in 1971, 1973 and 1974.
Document 13: Samantha Stosur: Samantha Jane "Sam" Stosur ( ; born 30 March 1984) is an Australian professional tennis player. She is a former world No. 1 in doubles, a ranking which she held for 61 weeks, and a former world No. 4 in singles.
Document 14: Elizabeth Smylie: Elizabeth Smylie (née Sayers, born 11 April 1963), sometimes known as Liz Smylie, is a retired Australian professional tennis player. During her career, she won four Grand Slam titles, one of them in women's doubles and three in mixed doubles. She also won three singles titles and 36 doubles titles.
Document 15: Radek Štěpánek: Radek Štěpánek (] ; born 27 November 1978) is a professional tennis player from the Czech Republic. His career-high singles ranking is world No. 8 and best doubles ranking is world No. 4. Štěpánek's biggest achievements are reaching two Masters 1000 event finals and the quarterfinals of Wimbledon in 2006, as well as winning the deciding match for Czech Republic's Davis Cup winning team in 2012 and again in 2013. In doubles, he won his first Grand Slam title at the 2012 Australian Open, along with Indian partner Leander Paes, defeating the Bryan Brothers in the final. Paes and Štěpánek also won the men's doubles title at the 2013 US Open, defeating Bruno Soares and Alexander Peya in the final.
ground_truth: Elizabeth Smylie