Perhaps you should try some spelling variations:
lang chai » lang ha, lang cua, lang phi
hoc viet » hoc hien
dan hanh » dang hanh, dan khanh, dan thanh
mang dai » lang dai, mang dat, mang dau
thuc dan » thuc hanh, hoc dan, thuc vat
nam thuc » nam thuoc, am thuc, nam thu
hiem he » hiem xe, thien he, hiem cho
hieu he » hieu ve, hieu le, hieu hien
sac ky » cac ky, sai ky
vi hoc » li hoc, va hoc
bo sac » bo sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: bo sac ky ((mang dai) or (lang chai)) hoi. ((hieu he) or (hiem he)) nam thuc dan hanh vi hoc viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo sac ky ((mang dai) OR (lang chai)) hoi. ((hieu he) OR (hiem he)) nam thuc dan hanh vi hoc viet.
• Adding a wildcard symbol may retrieve word variants: bo sac ky ((mang dai) or (lang chai)) hoi. ((hieu he) or (hiem he)) nam thuc dan hanh vi hoc viet*.