Perhaps you should try some spelling variations:
thuc dan » thuc hanh, hoc dan, thuc vat
vai cac » va cac, tai cac, voi cac
vai cau » va cau, van cau, lai chau
toc sac » toc sach, toc san, hoc sach
thuc va » thuc vat, thuc day
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
sac ky » cac ky, sai ky
va nam » van nam, ha nam, va nay

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sac ky lang xa hoi. hieu va nam ((thuc va) or (thuc dan)) dan ((vai cau) OR (vai cac)) treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sac ky lang xa hoi. hieu va nam ((thuc va) OR (thuc dan)) dan ((vai cau) OR (vai cac)) treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sac ky lang xa hoi. hieu va nam ((thuc va) or (thuc dan)) dan ((vai cau) OR (vai cac)) treo".
• Adding a wildcard symbol may retrieve word variants: toc sac ky lang xa hoi. hieu va nam ((thuc va) or (thuc dan)) dan ((vai cau) OR (vai cac)) treo*.