This blog post is not a credible source for a research paper, but that does not mean that it is not relevant.
The sources you use for a research essay should be factual. If you are quoting a written work with the intent of making it come across as true (for example to support your argument), it needs to be a credible piece of literature, like an article from an academic journal for example. The problem with this travel blog is that it is opinion more than fact. It is a narrative of what the author experienced and what her take on it is:
- "a history lover's paradise;"
- "fascinating corners;"
- "worth a visit;"
- "beautiful."
There is usually no rule banning the quoting of opinion pieces in research papers, however. For example, if you are writing about a political issue, you can compare speeches by representatives of both sides of the debate. The use you could make of this blog is to use it as inspiration for further research, because it does mention some monuments and places that you might want to include in your presentation of Amsterdam:
- "historic museums, churches, and parks;"
- "the Stedelijik Museum, Amsterdam Historisch Museum, and the Rijksmuseum;"
- "the house where Anne Frank and her family lived."