The great majority of the ingredients mentioned in the recipes are readily obtainable in Europe and North America. A few of the herbs may be elusive in the shops, if they are required fresh; but they can all be grown in the garden. Certain products, such as the smietana of Poland and the smetana of Russia, are only available in an approximately equivalent form โ in this instance, sour cream. But the difference is not important, and perfectionists will be able to find the very closest approximation, or even the real stuff, by consulting people of the relevant nationality, who can be counted upon to have gone into the matter.