Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
may hoi » may thoi, tay hoi, mai hoi
hiem he » hiem xe, hieu he, thien he
sach ky » sach y, sach ty, sach kem
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
sac ky » cac ky, sai ky
vi hoa » voi hoa, va hoa, bi hoa
vi hoc » li hoc, va hoc
he nam » ha nam, nghe nam

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((sach ky) OR (sac ky)) mang may hoi. hiem he nam thuc va danh ((vi hoa) or (vi hoc)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((sach ky) OR (sac ky)) mang may hoi. hiem he nam thuc va danh ((vi hoa) OR (vi hoc)) viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((sach ky) OR (sac ky)) mang may hoi. hiem he nam thuc va danh ((vi hoa) or (vi hoc)) viet".
• Adding a wildcard symbol may retrieve word variants: hoc ((sach ky) OR (sac ky)) mang may hoi. hiem he nam thuc va danh ((vi hoa) or (vi hoc)) viet*.