Sinusoidal signal generator circuit diagram electronic project

Using electronic diagram below can be made very simple sinusoidal signal generator using very cheap electronic components. This sinusoidal signal generator output voltage is relatively stable (at a level of about 4.5 Vvv).
With component values of C1 (C1 ') and R1 (R1), the output frequency will be about 300 Hz. Frequency can be modified by replacing it R1 and R1 'with a double potentiometer. To maintain frequency control between the limits, the entire field of variation of the potentiometer should not exceed: a decade.
The maximum frequency that can be obtained is about 5 kHz. Distortion will not exceed 0.1% and the current through the generator will be only a few milliamps.