When writing a thesis, the length of references may become a problem. A long list of references may make readers feel bored and not conducive to reading and understanding. Here are some ways to adjust the reference length:

1. Delete unnecessary references: First, you can check your reference list to see if there are any unnecessary references. For example, if your thesis mainly depends on several key research articles, then you may not need to list all relevant research. List only those documents that have a direct impact on your research.

2. Use abstract or overview: For some long references, you can consider using abstract or overview instead of full text. In this way, readers can quickly understand the main points and findings of these documents without reading the whole article.

3. Use online resources: There are many online databases and platforms that provide a lot of academic resources. You can use these resources to reduce the length of the bibliography. For example, you can use GoogleScholar or other academic search engines to find relevant online articles and papers.

4. Use the latest references: If your reference list contains a large number of outdated documents, you may consider updating your reference list. List only the latest literature that has a direct impact on your research.

5. Discuss with your tutor or peers: If you are not sure how to adjust your reference list, you can discuss with your teacher or peers. They may give you some useful advice.

Generally speaking, adjusting the length of references requires you to have a deep understanding of your research topic and be familiar with relevant documents. Only in this way can you effectively delete unnecessary quotations and ensure that your thesis still has sufficient academic depth and breadth.