Table:
text: Belgian International
Previous winners
Previous winners
Year_ Men_s_singles Women_s_singles Men_s_doubles Women_s_doubles Mixed_doubles
1978 No competition No competition No competition No competition No competition
1979 Ulrich Rost Marja Ridder Rob Ridder Piet Ridder Hanke de Kort Marja Ridder Rob Ridder Marjan Ridder
1980 No competition No competition No competition No competition No competition
1981 Barry Burns Carol Liem Ivan Kristanto Frank van Dongen Paula Kloet Grace Kakiay Bas von Barnau-Sijthoff Jeanette van Driel
1982 No competition No competition No competition No competition No competition
1983 Glen Milton Wendy Massam Peter Buch Niels Hansen Wendy Massam Lisa Chapman Rob Ridder Marjan Ridder
1984 Tariq Farooq Sally Podger Michael Fischedick Mathias Klein Sally Podger Lena Staxler Tsien Asjoe Jeanette van Driel

Question: When Marja Ridder won the women's singles at Belgian International, who then won the men's singles?