This configuration is from the 70s, having been found in an American documentation. The transistors can be BC549 for Q1 and BC548 for Q2.
The presented circuit was found in a 90’s Electronic Engineering. The circuit is based on CMOS...
We find the original version of this circuit in an English publication (1986). It is a...
Found in a 1990s Electronics Now, this circuit uses a period-specific integrated circuit that...