Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
sach ty » sach y, sach tu, sach thu
cuu tre » cua tre, cau treo
hanh ca » hanh cac, hanh cat, hanh cua
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
ma hoi » mai hoi, xa hoi, ma hoa

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 ma hoi. hieu va ((tac tu) or (cac du)) va hanh ca ((cuu tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ma hoi. hieu va ((tac tu) OR (cac du)) va hanh ca ((cuu tre) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ma hoi. hieu va ((tac tu) or (cac du)) va hanh ca ((cuu tre) or (cau tren))*.