Perhaps you should try some spelling variations:
cau tren » dau tren, ca tren, cau treo
danh cu » danh cau, danh tu, dinh cu
va danh » va dinh, va dan, va hanh
cao duc » dao duc, cao suc, giao duc
cu tren » tu tren, dua tren
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
sach v » sach va, sach 2, sach vay
va cao » va cac, va co, va dao

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 v) or (sach y)) nang xa hoi. hieu va cao duc va danh cu ((cau tren) OR (cu tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach v) OR (sach y)) nang xa hoi. hieu va cao duc va danh cu ((cau tren) OR (cu tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach v) or (sach y)) nang xa hoi. hieu va cao duc va danh cu ((cau tren) OR (cu tren))".
• Adding a wildcard symbol may retrieve word variants: toc ((sach v) or (sach y)) nang xa hoi. hieu va cao duc va danh cu ((cau tren) OR (cu tren))*.