Explaining Federalism: https://billmoyers.com/story/federalism-explained/
Explaining Unitary: https://vittana.org/12-unitary-system-pros-and-cons
Explaining Unitary: https://apecsec.org/pros-and-cons-of-unitary-government/
Explaining Confederate: https://vittana.org/11-pros-and-cons-of-articles-of-confederation
Explaining all 3: http://fhsboyd.weebly.com/uploads/5/5/6/2/5562296/__s1i_pdf_advantages_and_disadvantages_of_federal_confederate_and_unitary_systems_of.pdf
Explaining all 3: https://guides.skylinecollege.edu/c.php?g=279117
Academics Believe Unitary is Superior (specifically for non-large countries): http://www.bu.edu/sthacker/files/2012/01/Are-Federal-Systems-Better-than-Unitary-Systems.pdf
Interesting Mix
Decentralized Unitary states (Netherlands) https://www.tandfonline.com/doi/abs/10.1080/01402388708424654?journalCode=fwep20
Essay should be between 500 and 600 words, double-spaced and in APA format, with parenthetical citations and a Reference List. A cover page is not necessary.