"0, . "
"correspondence texts for units 1, 2 and 3: / " - 1 ed. - uk : open university 1973. - ", 72p.; 29 cm." - computing and computers .
0 335 01491 7
"correspondence texts for units 1, 2 and 3: / " - 1 ed. - uk : open university 1973. - ", 72p.; 29 cm." - computing and computers .
0 335 01491 7