Search the resources by combining source / subject(s) and layouts / full text. You do not have to fill all fields. While it is not possible for a resource to have two types of source (it is an article OR a blog post), it can have several subjects/layouts (dealing with history AND literature AND geographic layout). [Beta function]
*Tip: do not start right away by using full text search. You can sort the resources with specific filters and then, if there is too much, make a final sort according to the textual content. As the catalog only publishes short excerpts from the resources, this function is limited.