Finding a QSO based on a callsign or a date is easy. But DX4WIN has many more ways of finding QSOs. Using the Filter function, you can specify fields that will be used in the test if a QSO satisfies your search.

When the LogBook window is visible, it will only show the QSOs matching your search function.

Above: search for all 10M QSOs with zone 26. Fields that are blank will not be used in the test.

Above: search for all unconfirmed QSOs that have a USA state field and for which a QSL card was sent after Jan-1, 1995.