Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cau tren » dau tren, ca tren, cau treo
nam thuc » nam thuoc, am thuc, nam thu
sach ky » sac ky, sach y, sach ty
cuu tre » cua tre, cau treo
dan vai » dan va, dan tai, dan vat
cu tren » tu tren, dua tren
thuc va » thuc vat, thuc dan, thuc day
hieu ca » hieu cac, hieu cua, hieu va
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
ca nam » cua nam, cai nam, ha nam
va dan » ca dan, va dao, va dau

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

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