Perhaps you should try some spelling variations:
heats » cheats, heat, heads
hears » hearts, years, heart
spears » speaks, speare, speakers, shears, spars
spear » shear, speak, spar
sheath » heath
solution » solutions

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ((heats OR cheap) OR ((hears OR (spears OR spear)) OR sheath)) of mixing AND solution.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((heats or cheap) or ((hears or (spears OR spear)) or sheath)) of mixing and solution".
• Adding a wildcard symbol may retrieve word variants: ((heats or cheap) or ((hears or (spears OR spear)) or sheath)) of mixing and solution*.