Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
toc sach » hoc sach, doc sach, thuoc sach
tham luc » than luc, tham nuoc, nhan luc
sach va » sach xa, sach ha, sach dao
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
va nang » van nang, da nang, cam nang
va dan » ca dan, va dao, va dap
va dau » va dao
du cuu » tu cuu

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 va nang xa hoi. hieu va ((tham luc) OR (tham thuc)) ((va dan) or (va dau)) du cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach va nang xa hoi. hieu va ((tham luc) OR (tham thuc)) ((va dan) OR (va dau)) du cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach va nang xa hoi. hieu va ((tham luc) OR (tham thuc)) ((va dan) or (va dau)) du cuu tre".
• Adding a wildcard symbol may retrieve word variants: toc sach va nang xa hoi. hieu va ((tham luc) OR (tham thuc)) ((va dan) or (va dau)) du cuu tre*.