Hakim, A. (2014).(Online Image) Respiratory System - an overview | ScienceDirect Topics. Www.sciencedirect.com. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/respiratory-system

NIDDK. (2017, December). Online Image, Your Digestive System & How It Works. NIDDK. https://www.niddk.nih.gov/health-information/digestive-diseases/digestive-system-how-it-works

Endocrine Society of Australia. (2019, February 3). (Online Image) The Endocrine (or Hormonal) System. Hormones Australia. https://www.hormones-australia.org.au/the-endocrine-system/

Human Anatomy: Musculoskeletal System. (2024). (Online Image) Bibliocommons.com. https://sjpl.bibliocommons.com/events/670ab14208728d36000f3a30

Organismal Biology. (n.d.).(Online Image) Nervous Systems | Organismal Biology. Organismalbio.biosci.gatech.edu. https://organismalbio.biosci.gatech.edu/chemical-and-electrical-signals/nervous-systems/

Healthdirect. (2019, June 25). Immune system. (Online Image) Healthdirect.gov.au; Healthdirect Australia. https://www.healthdirect.gov.au/immune-system

National Cancer Institute . (2011, February 2). (Online Image) Reproductive system. National Cancer Institute. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/reproductive-system