Google Search – How to Escape Double Quotes Inside a Phrase Search

Perhaps this is because when linking to Google+ members the + is a prefix to the member name.

See, e.g, Google Kills Its Other Plus, and How to Bring It Back on Wired:

Google wouldn’t disclose exactly why they phased it out, though it seems obvious that they’re paving the way for Google+ profile searches. When Google+ launched, instead of adopting Twitter’s @reply syntax, they coined their own format for mentioning people — adding a plus to the beginning of a name — triggering the future conflict with the + operator.

Try Yandex. It's a Russian search engine providing the opportunity to search with an exact match as well as other options (for example searching a word by entering first X letters and leaving out last Y letters etc.). A useful article about searching in yandex: http://www.russiansearchtips.com/2015/04/yandex-ppc-match-type-operators-for-best-keyword-selection/