You either chain the devices (many of reset ICs having reset input), or wire-or them if they are open collector (OC - caution, if this is for '51, there appear to be too little true active-high OC output devices, I know only of the 770x).

Alternatively, you might try to experiment with logic gates, but watch out for the minimum power supply etc. (it is viable if you have battery around anyway).

JW