Two examples of intertextuality are as follows;
-The design of Tyrell's building is reminiscent of a Mayan temple, implying a god-like role in this world. (Heightened by the manner in which it is depicted, seperated from the city, omnipotent)
-One of the chess games within the film follows the exact sequence of a 1851 match known as 'The Immortal Game'. (I didn't find this one out myself.)
Although it's not really relevant to Tyrell, perhaps the advertising throughout the film can be seen as intertextual, seeing it's designed to convey 'reality', in the use of companies such as Coca-Cola and Atari. (Ironically, Atari faced economic crisis within two years of the film's production.)