Advanced searchAdvanced search is divided into two main parts, and one or more groups in each of the main parts. The main parts are the "Search for" (including) and the "Remove from search" (excluding) part. (The excluding part might not be visible until you hit "NOT" for the first time.)
You can add new groups to both the including and the excluding part by using the buttons "OR" or "NOT" respectively, and you can add more search options to all groups through the drop down menu on the last row (in each group).
For a result to be included in the search result, is it required to fit all added including parameters (in at least one group) and not fit all parameters in one of the excluding groups.
This system with the two main parts and their groups makes it possible to combine two (or more) distinct searches into one search result, while being flexible in removing results from the final list.