Custom search engines

I highly recommend setting up search keywords in your browser.

Setup

In Firefox: Settings > Search Shortcuts > Add
In Chrome: Settings > Manage search engines > Add
Set the link: anything containing %s, examples below, the %s is what will get replaced by your query.
Set the keyword: this is what you'll type in the address bar, then space, then your query, to call the search engine.

c C++ reference https://en.cppreference.com/w/Special%3ASearch?search=%s
man Linux manual http://www.die.net/search/?q=%s
p Python docs https://google.com/search?q=site%3Adocs.python.org+%s
j Java (SE and JDK) reference https://google.com/search?q=site%3Ahttps%3A%2F%2Fdocs.oracle.com%2Fen%2Fjava%2Fjavase%2F17+%s
s Google Scholar http://scholar.google.com/scholar?q=%s
dblp DBLP http://dblp.uni-trier.de/search?q=%s

k Kagi https://kagi.com/search?q=%s
g Google https://google.com/search?q=%s
gi Google Images https://images.google.com/search?q=%s
w English Wikipedia https://en.wikipedia.org/wiki/Special:Search?search=%s
wp Polish Wikipedia https://pl.wikipedia.org/wiki/Special:Search?search=%s
d English Wiktionary https://en.wiktionary.org/w/index.php?title=Special:Search&search=%s
dp Polish Wiktionary https://pl.wiktionary.org/w/index.php?title=Special:Search&search=%s
t Thesaurus http://thesaurus.com/browse/%s
l Ling.pl dictionary https://ling.pl/%s
a Wolfram|Alpha https://www.wolframalpha.com/input/?i=%s
y YouTube https://www.youtube.com/results?search_query=%s
ww English Wikipedia – internal stuff (docs, user/talk pages, ...) https://en.wikipedia.org/w/index.php?search=%s&fulltext=1&ns2=1&ns3=1&ns4=1&ns5=1&ns8=1&ns9=1&ns10=1&ns11=1&ns12=1&ns13=1&ns100=1&ns101=1

Alternatively, you might prefer setting DevDocs as your homepage.