This search engine is accent -sensitive but NOT case-sensitive.
You can search by keyword and related words by putting an asterisk at the end of the word root (searching for "energ*" you will find the terms "energy", "energetic", etc).
If you search using 'find any word', documents containing all the words will be shown first.
To search using operators or natural language, make sure to pick the option "Find exact phrase".
If you are looking for a subject section, check the site map, to find it quickly and easily.