Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
van hanh » van thanh, ban hanh, van anh
truc van » truc va, thuc van, truc ban
cam truc » cau truc, nam truc, lam truoc
sach va » sach xa, sach ha, sach dao
cua tre » cua te, cuu tre, cua triet
hanh de » hanh ve, hanh kem
vu sach » vu bach, su sach, vu khach
hieu va » lieu va, hieu qua
nang co » nang cao, nang doc, nang noi
nang o » nang ho, nang ro, nang x
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach va ((nang o) OR (nang co)) hoi. hieu va cam truc van hanh de ((cua tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach va ((nang o) OR (nang co)) hoi. hieu va cam truc van hanh de ((cua tre) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach va ((nang o) OR (nang co)) hoi. hieu va cam truc van hanh de ((cua tre) or (cau tren))".
• Adding a wildcard symbol may retrieve word variants: vu sach va ((nang o) OR (nang co)) hoi. hieu va cam truc van hanh de ((cua tre) or (cau tren))*.