Perhaps you should try some spelling variations:
nang dau » hang dau, xang dau, nang du
cham duc » pham duc, cham soc, pham duy
van tinh » van thinh, van minh, ban tinh
toan cua » than cua, tan cua, doanh cua
sach ty » sach y, sach tu, sach thu
dau hoi » cau hoi, dai hoi, dan hoi
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sac ky) or (sach ty)) nang dau hoi. hieu ve cham duc van tinh toan cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sac ky) OR (sach ty)) nang dau hoi. hieu ve cham duc van tinh toan cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((sac ky) or (sach ty)) nang dau hoi. hieu ve cham duc van tinh toan cua tre*.