You can resolve this situation by giving an advice to the class monitor... Those suggestions are as follows:
a) you can help the class monitor to search the book
b) you can explain about the situation to the class teacher and ask her/him for some help
c) you can ask all the students to search their bags, or if they find the book elsewhere ask them to return it to the class monitor
d) put it up in the school notice board
e) in case you do not find the book all students of the class can contribute some money and buy the same book and return it back to the respective person.
I hope this answer helps you...