Perhaps you should try some spelling variations:
hanh tri » thanh tri, hanh tai, hanh trinh
nang dai » nang dau, nang tai, lang dai
sach ky » sac ky, sach y, sach kem
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, sach thu
luc va » duc va, loc va
tuc va » thuc va, truc va, tuc xa
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: su ((sach ky) or (sach ty)) nang dai hoc. lieu va cam ((luc va) OR (tuc va)) hanh tri cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach ty)) nang dai hoc. lieu va cam ((luc va) OR (tuc va)) hanh tri cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (sach ty)) nang dai hoc. lieu va cam ((luc va) OR (tuc va)) hanh tri cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach ty)) nang dai hoc. lieu va cam ((luc va) OR (tuc va)) hanh tri cua tre*.