CREATE TABLE table_19681 ("Year" FLOAT, "Mens singles" TEXT, "Womens singles" TEXT, "Mens doubles" TEXT, "Womens doubles" TEXT, "Mixed doubles" TEXT)

Who won mens singles the year sveinn logi s lvason tryggvi nilsen won mens doubles and elsa nielsen won womens singles
SELECT "Mens singles" FROM table_19681 WHERE "Mens doubles" = 'Sveinn Logi Sölvason Tryggvi Nilsen' AND "Womens singles" = 'Elsa Nielsen'
SELECT "Mens singles" FROM "table_19681" WHERE "Mens doubles" = 'Sveinn Logi Sölvason Tryggvi Nilsen' AND "Womens singles" = 'Elsa Nielsen'