Perhaps you should try some spelling variations:
toan hanh » toan thanh, toan anh, tran hanh
qua giai » qua gia, luan giai, xuat giai
giai duc » giao duc, gia duc, giap duc
duc toan » duc tan, duc ton, duc hoan
hai cua » thai cua, dai cua, hoi cua
vai cua » dai cua, lai cua, bai cua
sach ly » sach y, sach lo, sach ty
nang xa » nang x, lang xa, nang ma
sach tu » sach thu, cach tu, sach ty

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 ly) or (sach tu)) nang xa hoi. hieu qua giai duc toan hanh ((vai cua) or (hai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ly) OR (sach tu)) nang xa hoi. hieu qua giai duc toan hanh ((vai cua) OR (hai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ly) or (sach tu)) nang xa hoi. hieu qua giai duc toan hanh ((vai cua) or (hai cua)) tre*.