Over the years I have build up a large collection of books (probably too many!) and out of all of these, the books I refer to most often and are usually on my desk are quotation books.
Not only do I find quotations a good way to start articles but also help to illustrate points I may want to make. Also, there are quotation books available on all sorts of subjects and it could be worth seeing if there are any available in the areas you write on.
One of the favourite quotation books I have was published over 100 years ago so I can hardly recommend this or give a link, but by looking in book shops, on ebay or Amazon you could find some that could be useful.
And, while on the subject of quotes, here is one from Peter De Vries,
I love being a writer. What I can't stand is the paperwork.
May I take this opportunity of thanking all who regularly visit my blog and although I realise only a very very few ever contact, here's wishing you all the very best with your own writing.