Add-ons

Open Library Search by jeffkaplan

Open Library: One web page for every book ever published.

Google.pt by portuguesemike

Search using Google.pt (Portugal).

Excel solutions for business by Business Spreadsheets

Find and download Excel templates and solutions for business analysis and productivity. Excel and spreadsheet based solutions from developers world wide are categorized based on their ability to facilitate business decision making and efficiency.

Reference - Reference.com by Jeremy Morton

Reference information at your fingertips.

Library of Congress Search by Sherlockian

Search The Library of Congress catalog.

Translate English to German by koula.koula

Translate english to german with google translate service.

Google Portugal by barcarossa

Search using Google in Portuguese (PT)

Scholar search (Google) by GNL!

Add search with Google Scholar to Firefox's search bar.
Tips:
1. Use Ctrl + up/down arrow to switch between installed search engines.
2. Use Ctrl + K to go directly to the search field.
3. Use manage (below engines) to switch the order of engines.

Worldwide German Google results by GlobalSearchTools

Do a Google search and get the results by language instead of by country.
You can search the entire german-speaking internet & find german websites worldwide.
Includes quicksearch: mark a word on any website, right mouseclick, search!

Collector's Note Fantastisches Werkzeug!

Smart Define Search by Smart Define

Add Smart Define to Firefox's search bar. Get a quick access to smartdefine.org dictionary and thesaurus when you need to find the best definitions and word meanings.

Freelancer.com by freelancer

Search the Freelancer.com database of projects for freelance workers.

lexisONE Citation Search by AttorneyTech

This search-engine add-on can be used to perform the Search by Citation feature on lexisONE to retrieve cases. No account is required to perform the search and view the results, but a free lexisONE account is required to read the full text of cases.

UniSearch by Topical Search

Search in academic institutions around the world