Context: CREATE TABLE table_14903999_1 (year INTEGER, mixed_doubles VARCHAR)
Question: What was the earliest year Þorvaldur Ásgeirsson Lovísa Sigurðardóttir won mixed doubles
Answer: SELECT MIN(year) FROM table_14903999_1 WHERE mixed_doubles = "Þorvaldur Ásgeirsson Lovísa Sigurðardóttir"