FREQUENCY DOMAIN ANALYSIS OF PERIODICALLY SWITCHED LINEAR CIRCUITS - Computer Methods for Analysis of Mixed-Mode Switching Circuits - page 243

The first-order approximation of the variation of capacitor current
due to a perturbation

gives

Inductors : In a like manner as that for capacitors, one can show that
for linear inductors

Controlled Sources : Consider a voltage-controlled voltage source
with voltage gain in N. Its counterpart in is a current-controlled
current source with controlling and controlled branches interchanged
and gain as shown in Chapter 3. Let the controlling and con-
trolled branches be identified with the subscripts 1 and 2, respectively.
Because

we have in the phasor domain