Zimmermann de Mergel, Margaret. <br/><br/>
Communication for business 
Margaret Z. Mergal. 
 - Río Piedras, P. R.  University of Puerto Rico Press  1974. 
 - 238 p. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Commercial correspondence<br/>English language--Business English.<br/>Letter writing