Check you have the correct author and title – it’s easy to make a mistake when looking for an old book. Watch out for common variations like McDonald/MacDonald or color/colour.

If the author’s name includes initials, just search by using their last name.

Books published since 1970 have ISBN numbers – you can search by ISBN on AbeBooks but a work can be published with multiple different ISBNs over the years so you may wish to do an author/title search.

Be prepared to order from overseas – copies may be plentiful in another country.

For older titles that are out of copyright, consider a print-on-demand edition where the book is created after your order is received and you are sent a brand new copy.

Books usually go out-of-print because they are no longer popular and sales have decreased. It's often a financial decision by the publisher.

Some books become dated and publishers decide to stop printing new copies. Travel guides, atlases, history books, and books about technology are particularly prone to this situation.

There can be disputes between the author and publisher, or the author can decide that a particular work should be not be reprinted - perhaps it's not their best writing or contains content they are no longer comfortable with.

Books do come back into print. Publishers will take this action when they think there is sufficient demand for a new edition. First published in 1965, Vincent and Mary Price's A Treasury of Great Recipes was out-of-print for decades before finally being republished in 2015.