Grammatically Correct: The writer's essential guide to punctuation ...

PUNCTUATION
By Mrs Hurst and Miss Bingley they were noticed only by a curtsey;
and, on their being seated, a pause, awkward as such pauses must
always be, succeeded for a few moments. It was first broken by Mrs
Annesley, a genteel, agreeable-looking woman, whose [endeavour] to
introduce some kind of discourse proved her to be more truly well­
bred than either of the others; and between her and Mrs Gardiner,
with occasional help from Elizabeth, the conversation was carried on.
-]ANE AusTEN, Pride and Prejudice
• In mathematical equations, various styles of brackets are used
to clarify which numbers are grouped with which. The placement
of parentheses and brackets is reversed from what it is with text,
with parentheses appearing within brackets. For example:
a = [(b + 1 )/(x)]- [(2b)/(x + 3)]
Other styles of brackets are curly brackets { } and angle brackets
< >, which are usually reserved for specialized uses in certain technical
and mathematical fields.
STYLE CONVENTIONS
• Don't leave spaces around the text enclosed by brackets [ like
this ]. Place the opening and closing marks directly next to the
text [like this].
• Unlike parentheses, brackets may be immediately preceded
by other punctuation, such as a comma. Simply treat the rest of
the quotation as you would if it still contained the original words.
Original quotation: Well, they may be in their infancy right now, but
there's some very exciting work being done on them.
Revised quotation: Well, [bibliographic visualization tools] may be in
their infancy right now, but there's some very exciting work being done
on them.
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