Perhaps you should try some spelling variations:
toan hanh » toan thanh, toan anh, tran hanh
thu sach » thuat sach, thuoc sach, thu hoach
dac toan » dan toan, duc toan, dac tan
mang tay » mang may, bang tay, quang tay
hieu ve » hieu va, hieu van
cac dac » cac dan, cac dai, cac bac
tu sach » su sach, te sach, tu cach
tay hoi » tay ho, tao hoi, tay thai
ky mang » ky nang, ke mang, ky dang
ve cac » va cac, vien cac
vi cua » vai cua, di cua

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) or (thu sach)) ky mang tay hoi. hieu ve cac dac toan hanh ((vi cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky mang tay hoi. hieu ve cac dac toan hanh ((vi cua) OR (dai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky mang tay hoi. hieu ve cac dac toan hanh ((vi cua) or (dai cua)) tre*.