Perhaps you should try some spelling variations:
te sach » toc sach
sach ky » sac ky, sach y, sach ty
vai cua » hai cua, lai cua, bai cua
hieu va » lieu va, hieu qua
ky hang » ky nang, ly hang, ky dang
va cam » va cham, va cac, va cao
lo van » le van, vo van, so van
va hoe » van hoe, va hoc, va hoa
lo va » lao va, ly va, le va

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky hang va hoe. hieu va cam ((lo va) OR (lo van)) dinh ((vai cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky hang va hoe. hieu va cam ((lo va) OR (lo van)) dinh ((vai cua) OR (dai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky hang va hoe. hieu va cam ((lo va) OR (lo van)) dinh ((vai cua) or (dai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky hang va hoe. hieu va cam ((lo va) OR (lo van)) dinh ((vai cua) or (dai cua)) tre*.