(a) What is academic writing

https://library.leeds.ac.uk/info/14011/writing/106/academic_writing
https://libguides.usc.edu/writingguide/academicwriting
https://slc.berkeley.edu/writing-worksheets-and-other-writing-resources/...
https://www.sydney.edu.au/students/writing.html  
https://www.sheffield.ac.uk/ssid/301/study-skills/writing
http://www.uefap.net/writing/writing-features/writing-features-introduction
http://www.uefap.net/writing/writing-functions/writing-functions-introdu...
https://writing.sites.caltech.edu/resources/collegewritingintro
https://explorationsofstyle.com
https://owl.purdue.edu/owl/general_writing/academic_writing/rhetorical_s...

(b) Types of academic writing

https://library.leeds.ac.uk/info/14011/writing/112/essay_writing
https://library.leeds.ac.uk/info/14011/writing/113/reflective_writing
https://library.leeds.ac.uk/info/14011/writing/114/report_writing
https://www.sydney.edu.au/students/writing/types-of-academic-writing.html
http://www.uefap.net/writing/writing-genre/writing-genre-genres
https://writeanything.wordpress.com/2009/08/26/observation/

(c) Writing Style

https://emedia.rmit.edu.au/learninglab/content/academic-style
https://writingcenter.unc.edu/tips-and-tools/style/
https://slc.berkeley.edu/writing-worksheets-and-other-writing-resources/...
https://libguides.reading.ac.uk/writing/style
https://libguides.reading.ac.uk/writing/stylesofwriting
https://www.ole.bris.ac.uk/bbcswebdav/courses/Study_Skills/grammar-and-p...
http://sana.aalto.fi/awe/style/index.html
http://sana.aalto.fi/awe/cohesion/index.html
https://students.unimelb.edu.au/academic-skills/explore-our-resources/de...
https://owl.purdue.edu/owl/general_writing/writing_style/style%20/Style%...
https://cmsw.mit.edu/writing-and-communication-center/analyzing-style/