I find the following source useful for sample letters. A sample apology letter is also included. See if it helps.
Microsoft Office has several templates for pre-written apology letters. The public library would be another great source for books with sample apology letters.
Apology letter to boss for absent without notice & for not receiving cell phone
Sample business letters include memos, letters of compliant and letters of resignation. Each one of these letters have their own formatting.
Never give an explanation letter for why you are late and absent. These will only be excuses. Write a letter of apology and assure that it will not happen again.
You can view sample sales letters at the link below.
There is actually a website, Best Sample Letters, that has links to all sorts of letter templates. Sample letters can also be found in Microsoft Office, Microsoft Works, and on the Microsoft website.
You can find sample business letters at www.legalforms.com. You aslo can find some sample letters at http://contracts.onecle.com/type/80.shtml.
sample of letters by liquidators to creditor in case of a company winding up
You can find several sample letter asking for assistance on the website GoBookee.
At the end of the letter write yours sincerely.
please check google and you can get thousands of sample letters, but make sure you use "sample application letter" as search key.