(21 days of C language basics! This is a hard book to find, although it is not very clear, it is still possible!
Twenty-one days to learn C language\!00001.pdg
Twenty-one days to learn C language\!00002.pdg
Twenty-one days to learn C language\!00003.pdg
Twenty-one days to learn C language\!00004.pdg
Twenty-one days to learn C language\!00005.pdg
Twenty-one days to learn C language\!00006.pdg
Twenty-one days to learn C language\!00007.pdg
Twenty-one days to learn C language\!00008.pdg
Twenty-one days to learn C language\!00009.pdg
Twenty-one days to learn C language\!00010.pdg
Twenty-one days to learn C language\!00011.pdg
Twenty-one days to learn C language\!00012.pdg
Twenty-one days to learn C language\!00013.pdg
Twenty-one days to learn C language\!00014.pdg
Twenty-one days to learn C language\000001.pdg
Twenty-one days to learn C language\000002.pdg
Twenty-one days to learn C language\000003.pdg
Twenty-one days to learn C language\000004.pdg
Twenty-one days to learn C language\000005.pdg
Twenty-one days to learn C language\000006.pdg
Twenty-one days to learn C language\000007.pdg
Twenty-one days to learn C language\000008.pdg
Twenty-one days to learn C language\000009.pdg
Twenty-one days to learn C language\000010.pdg
Twenty-one days to learn C language\000011.pdg
Twenty-one days to learn C language\000012.pdg
Twenty-one days to learn C language\000013.pdg
Twenty-one days to learn C language\000014.pdg
Twenty-one days to learn C language\000015.pdg
Twenty-one days to learn C language\000016.pdg
.....)