I am not a bookdealer, but the following information may help you find what you're looking for.
If there is no link in the margin on the left hand side of the book's title on the webpage then there is not an electronic copy available on the Internet, to the best of my knowledge, but I recommend you also check the On-Line Books site as its listings are more complete than mine. If no one has a link, you're down to looking for a paper copy...
Look it up in the US Library of Congress catalog, for British authors also try the British Library, for Canadian authors also try the National Library of Canada, for Australian authors also try the National Library of Australia, for New Zealand authors also try the National Library of New Zealand and for French & other European authors also try the Bibliotheque Nationale de France.
Thus armed with the publishing data (full title, full author(s)/editor(s) name(s), publisher, place & date of publication) you can then try getting a copy from Amazon or Barnes & Noble in the US, or Amazon or Blackwell's in the UK.
But it's better to use an availability & price-comparison service, such as AddALL BookFinder.com, bookfinder4u, BooksPrice.com Used Book Search .co.uk or Used Book Search .net, or the comprehensive book mart systems at abebooks.com & Alibris. Or you can use a second-hand book search service directly, such as HP Bookfinders, or try enquiring at a second-hand or antiquarian bookdealer specialising in the subject from the extensive list in the AcqWeb Directory.
Alternatively, try a book search service through a local second-hand or antiquarian book dealer, who you may be able to find in the Yellow Pages of big cities.
The price of second-hand books is strongly dependent on their condition, which the trade (at least in the UK) describe as:
There's also further advice on finding old books at Any Amount of Books.
Another possibility is to try borrowing it on Inter-Library Loan (or similar system) through your local public library or educational establishment's library.