"repotodocker" finds what you want the first result. "repo to docker jupyter" has your result as the first hit as well. It's not surprising "repo to docker" do

"repotodocker" finds what you want the first result. "repo to docker jupyter" has your result as the first hit as well. It's not surprising "repo to docker" doesn't find what you want, since there's a lot of sentences that have "repo to docker". Neither Bing nor DDG find what you want with that query either. So, you have jumped to the conclusion - the particular query is difficult, because your query doesn't give enough context to distinguish whether the query is against an entity or a partial phrase.