You should always evaluate information before you use it as a source in your work. You can use the following questions to help you with the evaluation:
The authors of a work – whether it is text, music, a picture, a sound recording or a web page – have copyright to the work. This means that others cannot publish it without the owner’s permission. According to the quotation rights, a part of a published work can be quoted.
For more information on how to quote appropriately, see Oamk’s instructions for writing and publishing a thesis.