Author-date referencing (or the Harvard system or Harvard style of parenthetical referencing) is common in articles published in Wikipedia, though Author-title referencing is also used in articles in Wikipedia; both styles are acceptable citation formats in Wikipedia.nder the author-date referencing system, a book is cited in the text in parentheses, after the section, sentence, or paragraph for which the book was used as a source, using the surname of the author and the year of publication only, with the parentheses closing before the period, as in (Author 2005) .
But John Hughes Benett was the first person to legally discovered leukemia in 1845 in Edinburgh. Later on, in the 19th century, many European scientists found out that there were some people who suffered from abnormal and excess production of white blood cells. They called it as weisses blut that means white blood.
What is leukemia? Leukemia is cancer that originates in blood-forming tissue. The disease is characterized by the uncontrolled growth of blood cells, usually white blood cells (leukocytes), in the bone marrow. White blood cells are a fundamental component of the body's immune response. The leukemia cells crowd out and replace normal blood and marrow cells.