My friend shared with me a Google document. This document includes some Greek symbols like tao, lambda, omega, sigma, etc. But I can't see these symbols! I also tried to search symbols by the menu ...
According to Google Basic search help Generally, most punctuation and special characters are ignored, however there is a growing list of punctuation and symbols that are recognized in searches. ...
Somewhat related to this question: When Google-searching a single special character, useful results are provided. For example, a query of "+" provides links to the Wikipedia article "plus and minus ...