If you select parameters from more than one box at a time, you will only get results that match all of the selected parameters. However, if you select multiple parameters within the same box (hold Ctrl/Cmd key and click items), then all of the relevant results will be returned.
If searches are not yielding enough results, try reducing the number of parameters you select. To cancel your existing search and start a new search, click on "Reset."
Once you find a program that interests you, be sure to read the brochure by clicking "Click to visit" next to "Homepage" at the top of the chart.