Sources

Layer 1: https://westpoppn.files.wordpress.com/2011/12/kids_in_class.jpg

and Spongegar image from SpongBob SquarePants

Layer 2: Background image taken from http://media02.hongkiat.com/coolest-libraries-in-the-world/new-york-public-library.jpg

Layer 3: Images taken from SpongeBob SquarePants

Layer 4: All images from Spongebob Squarepants

Layer 5: http://s3.amazonaws.com/rapgenius/filepicker%2FxYagbrST4elVKlAPXdPl_iphone_phone_ringing_.jpg

http://mkenyaujerumani.de/wp-content/uploads/2013/10/Lecture-Hall.jpg

and Spongegar image from SpongeBob SquarPants

Layer 6: Background image taken from https://pearlsofprofundity.files.wordpress.com/2013/09/gregorian-calendar-1.jpg

Layer 7: Background image taken from https://c1.staticflickr.com/3/2393/2306642057_3727de3973_b.jpg

Layer 8: Background image taken from: http://www.bevreview.com/wp-content/ontheshelf_mexican_coke_6pack_2.jpg