Silent Heroes is an action-packed, skillfully told, emotional and gripping Vietnam War story by retired U. S. Marine Corps Gunnery Sergeant Rick Greenberg, who served in an elite Reconnaissance Battalion in Vietnam from 1969 to 1970.Greenberg joined the Corps right out of high school because he always wanted to be a Marine. Little did he know what it would ultimately cost him to even approach earning such a title.After boot camp, "Greeny," as he was...