As we know, the mass of well known particles are below. $m_{n}\approx0.0000000000000000000000000016749286[kg]$ $m_{p}\approx0.0000000000000000000000000016726231[kg]$ $m_{e}\approx0.00000000000000000000000000000091093897[kg]$ I roughly know the way how to measure the electron's mass, but I don't know rest two of them. Any answers will be apreciated, Thank you.