“…Finally, by (40) we get, for j, k = 1, 2, ∂ 2 g kk ∂z k ∂z k = kkkk x 2 k + 4 kkk x k + 2 kk , ∂ 2 g kj ∂z k ∂z j = ∂ 2 g kk ∂z j ∂z j = kk j j x k x j + kk j x k + k j j x j + k j , (for k = j) ∂ 2 g jk ∂z k ∂z k = ∂ 2 g kk ∂z k ∂z j = kkk j z 2 kz kz j + 2 kk j z kz j , (for k = j), = 2222 = − 16m 3 e 8m(U −V ) 8 + 43mU + 19mV + 12m 2 4U V + 5U 2 + V 2 (1 + 2m(U + V )) 5 , ∂ 4 ∂ x 3 1 ∂ x 2 = 1112 = 16m 3 e 4m(V −U ) 2 + mU + 13mV + 24m 2 V 2 (1 + 2m(U + V )) 5 ,…”