The theorem can be applied to a network having a combination of voltage and current sources since voltage source can be converted into a current source and vice-versa.
The theorem is applicable only to two sources connected directly in parallel. It is not applicable where there are resistance elements between the sources.
The theorem is stated in the following manner :
“Any number of current sources in parallel may be replaced by a single current source whose current is the algebraic sum of individual source currents and source resistance is the parallel combination of individual source resistances”.