Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
hieu vu » hieu va, hieu ve, hieu su
vu cham » va cham, vu kham, tu cham
luc van » luoc van, luu van, luc va
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet

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 nang xa hoi. hieu vu cham ((luc van) OR (duc van)) doanh tai ((cua tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang xa hoi. hieu vu cham ((luc van) OR (duc van)) doanh tai ((cua tre) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang xa hoi. hieu vu cham ((luc van) OR (duc van)) doanh tai ((cua tre) or (cau tren))".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang xa hoi. hieu vu cham ((luc van) OR (duc van)) doanh tai ((cua tre) or (cau tren))*.