Useful words and phrases for essays

https://www.oxford-royale.co.uk/articles/words-phrases-good-essays.html

http://www.smart-words.org/linking-words/transition-words.htmlhttp://englishtutorhome2.blogspot.it/2013/03/how-to-write-essay-list-of-good-phrases.html

https://writing.wisc.edu/Handbook/Transitions.html#addition

http://englishtutorhome2.blogspot.it/2013/03/how-to-write-essay-list-of-good-phrases.html

http://fullspate.digitalcounterrevolution.co.uk/advanced-efl-essay-writing/advanced-essay-phrases.html

http://www.slideshare.net/englishbites/useful-argumentative-essay-words-and-phrases

http://www.essayzone.co.uk/blog/how-to-begin-a-new-paragraph-useful-linking-words-and-phrases/ 

Exercises

https://www.englishgrammar.org/linking-words-exercise-3/

https://agendaweb.org/grammar/conjunctions.html

https://www.english-grammar.at/online_exercises/connectives/connectives-index.htm

https://www.english-in-chester.co.uk/e-learning/lesson/linking-words/

https://www.perfect-english-grammar.com/linking-words-contrast-exercise-1.html

https://www.perfect-english-grammar.com/linking-words-reason-exercise-2.html

https://www.esl-lounge.com/student/grammar/4g67-linking-words.php