Perhaps you should try some spelling variations:
dan cong » dang cong, van cong, dan dong
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
mang xa » lang xa, mang may, dang xay
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac tac
cong cu » chung cu
cu tren » tu tren, dua tren
tuc va » thuc va, truc va, tuc xa
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: tu sach ty ((mang xa) or (nang x)) hoi. hieu va cac tuc va dan cong cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((mang xa) OR (nang x)) hoi. hieu va cac tuc va dan cong cu tren.
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((mang xa) or (nang x)) hoi. hieu va cac tuc va dan cong cu tren*.