I'm trying to understand source transformation and with my research, I have had some confusion. I have two question regarding them and would appreciate any help. I understand that the thevenin resistance is found by short circuiting the voltage source. Is that also the case when you short circuit the current source? What if it has both sources, what resistance do we find when we short circuit them? By using source transformation, can we only change to voltage source if the current source and the resistors are in parallel? Thanks in advance.