Why is it so difficult to remove oil from bird feathers? Why can water birds drown if they still have detergent on their feathers? - Chemistry bibliographies - in Harvard style

In-text: (Try Dawn dish soap for unbelievably clean dishes. Eliminate grease and leave your dishes sparkling clean with Dawn dishwashing liquid., 2018)

Your Bibliography: Dawn-dish.com. 2018. Try Dawn dish soap for unbelievably clean dishes. Eliminate grease and leave your dishes sparkling clean with Dawn dishwashing liquid.. [online] Available at: <https://dawn-dish.com/en-us> [Accessed 12 June 2018].

In-text: (Uropygial gland, 2018)

Your Bibliography: En.wikipedia.org. 2018. Uropygial gland. [online] Available at: <https://en.wikipedia.org/wiki/Uropygial_gland> [Accessed 4 June 2018].

In-text: (Fuller, 2015)

Your Bibliography: Fuller, M., 2015. The structure and properties of down feathers and their use in the outdoor industry - White Rose eTheses Online. [online] Etheses.whiterose.ac.uk. Available at: <http://etheses.whiterose.ac.uk/9268/> [Accessed 4 June 2018].

In-text: (Kopeliovich, 2013)

Your Bibliography: Kopeliovich, D., 2013. Surfactants [SubsTech]. [online] Substech.com. Available at: <http://substech.com/dokuwiki/doku.php?id=surfactants> [Accessed 7 June 2018].

In-text: (Kopeliovich, 2013)

Your Bibliography: Kopeliovich, D., 2013. Surfactants [SubsTech]. [online] Substech.com. Available at: <http://substech.com/dokuwiki/doku.php?id=surfactants> [Accessed 7 June 2018].

In-text: (Venzel, 2016)

Your Bibliography: Venzel, S., 2016. Anatomy of a Feather: Learn How They Are Pretty with a Purpose. [online] Wide Open Pets. Available at: <http://www.wideopenpets.com/pretty-with-a-purpose-the-anatomy-of-a-feather/> [Accessed 2 June 2018].

In-text: (Zielinski, 2011)

Your Bibliography: Zielinski, S., 2011. Should Oiled Birds Be Cleaned?. [online] Smithsonian. Available at: <https://www.smithsonianmag.com/science-nature/should-oiled-birds-be-cleaned-29931181/> [Accessed 28 May 2018].