A course of higher mathematics Vol. 3. part 2, Complex variables, special functions ; translated by D.E. Brown ; translation edited by I.N. Sneddon.

No folly in folic acid. Folic acid should be taken regularly by all pregnant mums and people with a low immunity to disease. Folic acid prevents spina bifida in unborn babies and can play a role in cancer prevention. It is found in green leafy vegetables, liver, fruit and bran.