Take your book at page 50. vs Take your book on page 50

Some examples from the web:

• Open your book at page one.
• You move through the girlfriend no later than page 50.
• (Chips clatter) You move through the girlfriend no later than page 50.
• We've been talking about your book at school.
• They found a signed copy of one of your books at Kay's house.
• My friend Augustus read your book at my received an email from you at this address.
• I saw your book at a Target
• I'll take your book out from under my piano.
• Settle down, take your books.
• Take your books home over the weekend.
• Will you open your grammar books at page 94?
• All right, then, leave and take your book with you.
• Go. Take your book with you.
• She's demanding you take your book off the shelves?
• Directive 2004/18/ EC of the European Parliament and of the Council of 31 March 2004 on the coordination of procedures for the award of public works contracts, public supply contracts and public service contracts - Page 50.
• Are you ever worried somebody might take your book wrong and try to kill someone like when that guy tried to shoot R. Reagan after reading Catcher in the Rye?
• The information relating to this aid scheme can be found on page 50 of that document.
• Turn to page 50 ladies, for today's is the recipe...
• What's the last line on page 50?
• on page 50, Article 13:

Some examples from the web:

• Open your books on page 100.
• The information relating to this aid scheme can be found on page 50 of that document.
• What's the last line on page 50?
• on page 50, Article 13:
• on page 50, entry I5 of the table:
• Your book on Wendy is dead.
• I read your book on neuroanatomy in med school.
• I hear your book on Marcus Aurelius has the whole community astir.
• I've read your books on profiling.
• I loved your book on the Tunguska event of 1908.
• I read your book on art therapy.
• Your book on Kevin Clark doesn't have an ending.
• You cannot and you will not sell your books on school grounds.
• We love listening to your books on tape.
• I hear your book on Marcus Aurelius has the whole community astir.
• Okay, class, open your books. Let's begin on page one.
• On page 50, in the Annex, in point 3, column I:
• on page 50, Article 1(2), in the table:
• on page 50, the second subparagraph of Article 52(2):
• I'll take your book out from under my piano.