We found this circuit in the Radio Electronics magazine of May 1977. The circuit has the frequency given by the components according to the formula next to the diagram.
This circuit shows how a monostable can be obtained from an RS flip-flop using a unijunction...
This circuit was found in an application note of the LTC1164 from Linear Technology of the 1990s....
Using a general-purpose transistor this AC amplifier was found in the November 1993 issue of...