• https://scholar.mzumbe.ac.tz/items/115707a6-6692-4c04-8ac5-ef38baec6c60
• https://scholar.mzumbe.ac.tz/items/dab501a2-5b0d-4a81-8b5a-b9f4eaaf1b6f
• https://scholar.mzumbe.ac.tz/items/f7c8b789-fd29-4164-abea-6921a2f10bf8
• https://scholar.mzumbe.ac.tz/items/7c92e7a3-bbe9-4618-b95d-e2112156910c
• https://scholar.mzumbe.ac.tz/items/013067bd-2c72-4f1f-8ada-1c785df4ed0a
• https://scholar.mzumbe.ac.tz/items/da821861-338c-478e-9ae0-8100d6aedbf2