First, you have to think about how you want to identify your sources.
If your sources are very important to your ideas, you should mention the author and work in a sentence that introduces your citation.
However, if you have cited other sources and then go back to one you had cited earlier, it is a good idea to mention at least the author's name again (and the work if you have referred to more than one by this author) to avoid confusion.
Taking the exact words from an original source is called quoting.
For example, the following sentence puts information about the author and work before the quotation: Milan Kundera, in his book The Art of the Novel, suggests that “if the novel should really disappear, it will do so not because it has exhausted its powers but because it exists in a world grown alien to it.” You may also want to describe the author(s) if they are not famous, or if you have reason to believe your reader does not know them.
You should say whether they are economic analysts, artists, physicists, etc.
In those cases you should add the complete URL (http ://....) and access date, the date you downloaded/read the book. Corporate lobbying is blocking food reforms, senior UN official warns.
Some books whose copyright have expired are sometimes freely available on the internet. Today the publisher often states how to write the reference. Economic Restructuring into Tourism in the Swedish Mountain Range. If the URL is very long it could be sufficient to use the URL of the newspaper e.g Jowit, Juliette . Organisation for Economic Co-operation and Development (OECD).
If there is no author, use the title of the entry or article first. If possible always state the creator of the illustration in the reference list. If available also provide page number of the illustration: Hazel, Edward.. If possible state the name of the artist and the collection: Turner, Joseph.
For articles/entries in online encyclopedias include (if available): author of article, title of article, name of encyclopedia, year of publishing,; complete URL ( and date of access. In those cases you need permission from the copyright owner before you can you use the illustrations in your text. State the name of the illustrator if different than the author of the work. If you have viewed an image of a work of art online, you should reference it as an online image, regardless of the original medium.