APA
National Council of Educational Research and Training(NCERT), . (2006). Biology: textbook for class XIth. New Delhi: National Council of Educational Research and Training(NCERT).
Chicago
National Council of Educational Research and Training(NCERT), . 2006. Biology: textbook for class XIth. New Delhi: National Council of Educational Research and Training(NCERT).
Harvard
National Council of Educational Research and Training(NCERT), . (2006). Biology: textbook for class XIth. New Delhi: National Council of Educational Research and Training(NCERT).
MLA
National Council of Educational Research and Training(NCERT), . Biology: textbook for class XIth. New Delhi: National Council of Educational Research and Training(NCERT). 2006.