Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
cau tren » cu tren, dau tren, ca tren
dat tren » dat trong, dua tren
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
lieu ha » lieu nha, lieu va, lieu ma
thuc va » thuc vat, thuc dan, thuc day
han tai » hang tai, nhan tai, van tai
va han » va phan, van han, va hanh

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang xa hoi. ((lieu ha) OR (liem ha)) nam thuc va han tai ((cau tren) or (dat tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. ((lieu ha) OR (liem ha)) nam thuc va han tai ((cau tren) OR (dat tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. ((lieu ha) OR (liem ha)) nam thuc va han tai ((cau tren) or (dat tren))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. ((lieu ha) OR (liem ha)) nam thuc va han tai ((cau tren) or (dat tren))*.