The Billings method : using the body's natural signal of fertility to achieve or avoid pregnancy /
Billings, Evelyn.
Westmore, Ann.
NHS Health Scotland.Library,former owner.StEdNL
Leominster : Gracewing,
2000.
Includes erratum slip.
Label on cover and t.p.: Health Scotland Library, NHS Health Scotland, The Priory, Canaan Lane, Edinburgh...