Perhaps you should try some spelling variations:
heats » heat, heads, seats
cheats » cheat, cheads, cseats
heath » death, heat
cheath » cdeath, cheat, sheath, creath
cheads » heads, aheads, cheaps
chears » clears, hears, shears

Try widening your search to All Fields.

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 heath) OR ((((cheads OR chears) OR cheats) OR cheath) OR cheath)) of mixing AND (solution" or solutions").
• The words AND, OR and NOT may confuse the search; try adding quotes: "\"((heats or heath) or ((((cheads OR chears) or cheats) or cheath) or cheath)) of mixing and (solution\" or solutions\")".
• Removing quotes may allow a broader search: ((heats or heath) or ((((cheads OR chears) or cheats) or cheath) or cheath)) of mixing and (solution or solutions ).
• Adding a wildcard symbol may retrieve word variants: "((heats or heath) or ((((cheads OR chears) or cheats) or cheath) or cheath)) of mixing and (solution" or solutions")*.