I can't find the deaths of some ancestors.

Their names were Joseph Campbell (born about 1837/8) and Sarah Campbell nee Woods (his wife born about 1859/60). They married in Leckpatrick Presbyterian Church in January 1860, Joseph was a Shoemaker and living in Ballymagorry, Strabane, and Sarah was living in Woodend. Only their fathers names are given William Campbell a Corn Dealer and Allen Woods a Farmer.

The last I knew of Joseph being alive was the birth of their youngest child in December 1871, he had died by October 1898. But I know Sarah died between 1898 and June 1905, because on her son Thomas' 1898 Scottish marriage certificate it says Joseph is deceased and Sarah isn't but on Thomas' Scottish death certificate it says she is dead.

Thanks.