CK-12′s websites and textbooks are available free of charge. You can view them online with your browser, or use them with a PDF reader. If you choose to print a FlexBook ® textbook, you simply pay the printing costs.
CK-12′s websites and textbooks are available free of charge. You can view them online with your browser, or use them with a PDF reader. If you choose to print a FlexBook ® textbook, you simply pay the printing costs.