If academic writing is new for you, or if you normally do it in a language (or languages) other than English, one of the challenges of writing a thesis or an article for a scholarly journal is knowing the right words to use to connect your ideas and to explain why what you are writing about is important. While the best way to learn the vocabulary of academic writing is by reading good examples, a useful reference is the online Academic Phrasebank from the University of Manchester. This is also a great reference for legal English writing or writing for business.
You can choose the function of the language you need and the site suggests academic language, along with examples of the academic phrases in use. For example, one of the categories listed is 'Explaining Causality'. That's an important function for legal English writing. The site then lists useful language divided into categories like nouns indicating causality (such as a consequence of) or prepositional phrases indicating causality (such as owing to). It shows several examples of the language used in context.