This is sentence from Design of Analog CMOS Integrated Circuit that I don't understand.
Note that the current source injects current into ground or draw current from VDD. In other words, only one terminal of each current source is "floating".
Does this mean that, for a MOSFET to be used as a current source, the source of an NMOS should be connected to ground and the source of an PMOS should be connected to VDD? No other cases are possible? I mean for example for NMOS, the source may be connected to something else than to ground.