One of the uses to which almost all of us frequently put the English language is the writing of letters-personal, business, or poison-pen. All sorts of books have, therefore, been published, advising us how to write letters courteously and effectively. Such books invariably include model our condolences. Each potential uses of these exemplars must, of course, modify them to suit his or her particular circumstances, needs and preferences.
Borgmann, Dmitri A.
Word Ways: Vol. 38
, Article 5.
Available at: http://digitalcommons.butler.edu/wordways/vol38/iss4/5