Where are the names of all the spells stored?

Dear friends, could you tell me where the names of all spells are stored? For example, I want to give a certain skill (Magic Arrow, or God forbid Armageddon or Implosion) to a regular unit. Usually I just looked for this skill in other units and copied the spell line, but for example, Magic Arrow isn't in anyone's list (if my memory serves me right). Could you tell me where I can look up all these skills? I mean skill names like these:          <Spell>SPELL_SLOW</Spell>
<Mastery>MASTERY_ADVANCED</Mastery>"

I think they should be looked up somewhere among the heroes, but I haven't found them. Thanks in advance.