Correct Usage of Quotation Marks in Academic Writing.
I think your solution of including the explanation of what the acronym GCHQ means by using square brackets within the quote is an elegant one, especially if there is no earlier opportunity to spell out the acronym. Depending on the style and length of your essay, another option would be a footnote.
Free guide to harvard referencing style from Essay UK. Harvard referencing. The HARVARD system cites the author's surname and year of publication in the text, e.g. (Bond, 2004), and provides a reference list (of these citations), in alphabetical order by author, at the end of the assignment.
A four-dot ellipsis is actually an ellipsis with a period at the end of it. It’s important to remember that you still should punctuate properly even if you’re using an ellipsis. When using ellipses in conjunction with other punctuation, whether they be commas, semicolons, question marks, or exclamation points, treat the ellipsis as though it was just another word in the sentence.
The following comes from the Purdue Online Writing Lab's MLA Formatting and Style Guide. Go here to check it out for their citation of the original MLA handbook. If you add a word or words in a quotation, you should put brackets around the words to indicate that they are not part of the original text.
A picture is worth a thousand words, and sometimes an illustration is exactly what you need in your paper to drive an argument home and communicate your point succinctly. Avoid using images to pad.
FYI—I updated this article on Jan. 15, 2015. The topic of character thoughts has come up repeatedly for me in the last couple of weeks, and I promised to address punctuation for inner dialogue. Inner dialogue is simply the speech of a character to himself. He hears it and the reader hears it, but other characters have no idea what’s going on in his head.
To quote a critic or researcher, you can use an introductory phrase naming the source, followed by a comma. Note that the first letter after the quotation marks should be upper case. According to MLA guidelines, if you change the case of a letter from the original, you must indicate this with brackets. APA format doesn't require brackets.