Perhaps you should try some spelling variations:
chet duc » chet duoc, viet duc, che duoc
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
ve chet » ve chat, ve che, se chet
duc van » duc va, duc tan, duc manh
lai cua » hai cua, lai chau, thai cua
y nang » ky nang, ly nang, v nang

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 y nang ma hoa. hieu ve chet duc van hanh ((lai cua) or (dai cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ma hoa. hieu ve chet duc van hanh ((lai cua) OR (dai cua)) te.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ma hoa. hieu ve chet duc van hanh ((lai cua) or (dai cua)) te*.