(3GdehShYI GdcdGScjI ddeSQM GdjhfGfi hGdQheGfi(B((3eSQMjGJ jhQjHjOjS(B) / s - (3Gejf SdGeIs ([S.N] : (3ecJHI eOHhdi , s, 1988)
Keywords: (3GdGOH GdjhfGfis; (3GdGOH GdQheGfis; (3GdeSQMjGJ GdjhfGfjIs; (3jhQjHjOSs