Answer:
1. Therefore, However and Then
2. Refer to it, Paraphrase it, Summarize it, Use someone else's ideas
Explanation:
1. "Therefore", "However" and "Then" are words that indicate that you are finalizing a thought by concluding on all the facts, evidence and arguments addressed in relation to a given subject. These words should always be used in an essay or speech at the time the author's position is being finalized and a resolution is being applied.
2. You must cite the sources of research in an article whenever you use elements written by other authors or even mention those elements or the author. This prevents you from committing plagiarism and allows your work to be considered correct and legal. In summary, you should cite the sources whenever you refer to it, paraphrase it, summarize it or use someone else's ideas