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.
Leukemia is cancer of the white blood cells. White blood cells help your body fight infection. Your blood cells form in your bone marrow. In leukemia, the bone marrow produces abnormal white blood cells. These cells crowd out the healthy blood cells, making it hard for blood to do its work. There are different types of leukemia, including