What is copyright? No one can reproduce your work with- out your permission - not even a personal letter. How much of a writer's work can be legitimately used? A poem of 40-50 words is generally considered to be OK. Usually one is not allowed to copy substantial amounts of another writer's work without their express permission.
* But then what is meant by word "substantial"? It is widely open to interpretation and opens up a literary and legal "minefield" (that's a metaphor, by way!).
There are no hard and fast guidelines about rule of copy- right. The following is a rough 'rule of thumb':
You can take approximately 300 words from a book or any other lengthy work of writing. You can also quote 150 words from a magazine article. Fifty (50) words quoted from a news- paper article is generally considered to be "fair use" without requiring either permission or a fee. Copyright lasts 50 years after your death.
You can use what is termed 'fair dealing' in writing reports, or researching material. I always advise acknowledging sources in your reference section (the bibliography - I tried very hard to bring in that impressive long word) .
It's all very unclear - entire subject of copyright; so I won't say too much. My simple words of advice are: Just use your common sense and discretion (if you have some)... and be HONEST by fol- lowing your heart. Don't copy other author's material and purport (nice word, eh?) to be author. One should not paraphrase a substantial amount of another author's writing, nor use that writer's points (or theme of their writing) without due ACKNOWLEDGMENT. Hint hint!
If you get into a dispute (oops!), there are specialised trade and copyright laywers (or solicitors as they call them here in 'civilised' NZ) in big centres. If in doubt, get advice...then DON'T infringe copyright.
Send requests to use "borrowed" material to permissions editor of a magazine, newspaper or book publisher. Book publishers usually have a small department which deals solely in this. Give them as much information as possible about your article or book, your publisher, as well as other books or articles written by you. Tell them what quotes you want to use and why and so on. Say you will give them due acknowledgement in your writing. They'll usually oblige.