00338nam a2200121 a 450000500170000002000150001708200150003210000060004711000520005324500450010526000400015030000260019020251203110925.0  a0070616825  a004.6bISR  d_  aInstructional software research and development  aData communication and computer networks  aNew DelhibTata McGraw - Hillc2007  axixc340p.c24 cm. PB