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Abebooks is the world's largest online marketplace
for books. Whether it's new, used, rare, or out-of-print, you can find it here,
through our community of over 12,000 independent booksellers from around the
globe. Abebooks (formerly just ABE) is a single-access storefront through which
those 12,000-plus used-book dealers--many true mom 'n' pop operations--can make
their entire stock available anywhere in the world. Practically every used-book
shop that does sell on the internet belongs to Abebooks: if you use a used-book
meta-search engine (an engine that searches the results of other search engines) to
look for used books, you will only rarely find anything that is not listed on
Abebooks, wherever else it may be listed.
"Boolean" searches (named after logician George Boole) let you use use the words
and, or, and not--called "logical operators"--plus quotation
marks and parentheses to construct more-exact queries. You can turn Boolean
searching on or off using the radio buttons next to the phrase search with
Boolean searching in the Search Box above (it defaults to being off). If
it is off, those words have no "magic" meaning, whereas if it is on
they act to combine search terms in special ways.
Note 1: When Boolean Searching is on,
the tilde symbol ~ can be used in place of the word not.
Note 2: You don't have to upper-case the
Boolean terms--in the examples below, we just do it for emphasis.
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Examples of Boolean Searching:
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You are looking for books about warfare, and want to find books dealing with
"war" or with things "military" in nature. The Boolean logic is OR:
· do a Keyword search for war OR military
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You are looking for a book about cats and painting. The Boolean logic is
AND:
· do a Keyword search for cats AND painting
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You're looking for books by an author named King, but who is not
Stephen King. The Boolean logic is NOT:
· do an Author search for King NOT Stephen (or
for King ~Stephen, using the tilde to mean not)
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You want to search for either or both of the books To Have and Have Not
and The Old Man and the Sea by Ernest Hemingway. The Boolean
logic is OR:
· use Author search for Ernest Hemingway combined
with
Title search for "To Have and Have Not" OR "The Old
Man and the Sea"
(This example illustrates a subtlety, and the wise use of quotation marks.
In this example, there were words that normally are Boolean operators
within the titles of the books. You wanted the search to look for the
actual book titles, not to interpret those title words--and and
not--as Boolean operators. To tell the search that you are looking
for titles, you must use quotation marks (" ") around any
Boolean operators that you do not want considered as Boolean
operators.
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You're looking for for volumes of Harry Potter published by different
publishers. The Boolean logic is OR, AND:
· do a Keyword search for (Scholastic AND Harry Potter)
OR (Bloomsbury and Harry Potter)
This example demonstrates how to group series of words together: use
parentheses ( ). As in mathematics, use of parentheses will keep
search terms together as a block or unit.
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"Operator: precedence:
The Boolean operator "not" is given the highest precedence, followed by
"and", and then "or". If you have two Boolean operators in one
search, the search will be run using the order of precedence. For example: You are
searching for a book by Stephen King. You don't want the book "IT", but
do want books by Penguin publishers. The search results you see will display any
books that match your criterion.
Parentheses can be used to force the order of processing. For example:
Keyword search: (Bloomsbury OR Scholastic) AND Harry Potter
By surrounding the OR words with parentheses, you force the search engine to
process the two related terms (the pair in the parentheses) first. Only after that
will the search engine combine tat firsts result with the last part of the search.
Using this method, the related OR terms are kept together as a logical unit.
Invalid Boolean Searches:
The following Boolean searches are invalid and would not be completed because the
search expression is incomplete:
Keyword search: Cat NOT
Author search: Stephen OR NOT King
Title search: NOT the shining
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