This circuit with power MOSFETs was found in a 1980s Siliconix documentation. Equivalent MOSFETs can be used, as well as other transistors. Note the symmetric power supply.
Found in a 90's EDN, this circuit generates signals in the frequency range given by the graph. The...
Found in Harris' 90s documentation, this circuit uses a zener as a stabilizer. The signals...
We found this circuit in a 90s Electronic Design. The circuit is based on a quadruple operational...