${\partial }^{\gamma \dot{\gamma }}{\partial }_{\gamma \dot{\gamma }}{\phi }_{{\alpha }_1...{\alpha }_k{\dot{\beta }}_1...{\dot{\beta }}_n}^{\left(k,n\right)}=2e^2{m}^2{x}^{{\alpha }_{k+1}{\dot{\beta }}_{n+1}}{x}^{{\alpha }_{k+2}{\dot{\beta }}_{n+2}}{\phi }_{{\alpha }_1...{\alpha }_k{\alpha }_{k+1}{\alpha }_{k+2}{\dot{\beta }}_1...{\dot{\beta }}_n{\dot{\beta }}_{n+1}{\dot{\beta }}_{n+2}}^{\left(k+2,n+2\right)}$