# 2d. Additional Search Methods
## Introduction
When you have set up a good keyword search strategy, it can be helpful to add some additional ways of searching to your strategy to help you find more literature. We recommend you use these techniques as an addition to your keyword search and not as a replacement. This is because a keyword search is the most rigorous way to find the largest amount of relevant literature.
Techniques you could use in addition to keyword searching are: Snowballing and Similar Document Searching.
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:gutter: 2
:::{grid-item-card} Step 1
[Snowballing](#step-1-snowballing)
Track the citations of an academic article to find more results
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:::{grid-item-card} Step 2
[Similar Document Searching](#step-2-similar-document-searching)
Use similar document searching in Dimensions to find more papers
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## Step 1: Snowballing
Snowballing means finding more results based on the citations of highly relevant publications. There are two types of snowballing: When _forward snowballing_, you can find other relevant articles by looking at which publications cite a specific key publication.
In _backward snowballing_, you take a very recent key article and find more relevant results by looking at the references made by this key article.
Watch the first part of this brief explainer to learn in detail how to use these additional ways of searching:
"Additional Ways of Searching" by TU Delft Library Education Support is licensed under CC-BY
## Step 2: Similar Document Searching
Using similar documents searching in Dimensions helps to find new relevant articles based on a relevant abstract or your thesis plan.
Watch the second part (starts at 2:44) of this brief explainer to learn in detail how to use this additional ways of searching:
"Additional Ways of Searching" by TU Delft Library Education Support is licensed under CC-BY