Clebsch–Gordan series is the expansion of the tensor product of two irreducible representation into direct sum of irreducible representations. D ( p 1 , q 1 ) ⊗ ⊗ D ( p 2 , q 2 ) = ∑ ∑ P , Q ⊕ ⊕ D ( P , Q ) . This can be easily found out from the Young tableaux.