Research and Studies Database at the National Information Center - Yemen.
A great site with many free and paid tools, allows you to create questionnaires and electronic surveys in more than one language, including Arabic and English.
The site contains several scientific tools for researchers in English.
Site to manage and record references and quotations.
Site to create graphs.
The site combines several scientific journals with open access.
Academic Search Engine.
ٍSearch engine for scientific journals.