Does anyone have sources?

Merriam-Webster:
Main Entry: hel·lo
Pronunciation: h&-'lO, he-
Function: noun
Inflected Form(s): plural hellos
Etymology: alteration of hollo
Date: 1889
: an expression or gesture of greeting -- used interjectionally in greeting, in answering the telephone, or to express surprise

and

Main Entry: hol·lo
Pronunciation: hä-'lO, h&-; 'hä-(")
Variant(s): also hol·loa /hä-'lO, h&-/; or hol·la /h&-'lä, 'hä-(")/
Function: interjection
Etymology: origin unknown
Date: 1588
1 -- used to attract attention (as when a fox is spied during a fox hunt)
2 -- used as a call of encouragement or jubilation

Are you trying to discredit me?