$C^\infty$ equivalence and complex analytic equivalence between elliptic surface

Question

In Friedman and Morgan's book about elliptic surface, the authors claimed that $C^\infty$ isomorphism between elliptic surfaces $A$ and $B$ doesn't imply that $A$ and $B$ are deformation equivalent, so $A$ and $B$ may not be isomorphic as complex manifolds. But is there any specific example that two elliptic surfaces are $C^\infty$ isomorphic but not isomorphic as complex manifold?