Perhaps you should try some spelling variations:
heats » heath, seats, beats, heads
cheats » cheath, cseats, cbeats, cheads, cheat
heat » head
sheath » sheadh, heath
cheads » aheads, chears, cheaps, cleads
heads » leads

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 heat) OR (((cheads OR heads) OR (cheats OR sheath)) OR sheath)) of mixing AND (solution" or solutions").
• Removing quotes may allow a broader search: ((heats or heat) or (((cheads or heads) or (cheats or sheath)) or sheath)) of mixing and (solution or solutions ).
• Adding a wildcard symbol may retrieve word variants: "((heats or heat) or (((cheads or heads) or (cheats or sheath)) or sheath)) of mixing and (solution" or solutions")*.