Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
dinh vai » dinh van, dinh vi, dinh va
dan dinh » dang dinh, doan dinh, van dinh
thuc dan » thuc hanh, hoc dan, thuc vat
tang mai » tang ma, tang tai, lang mai
vai cua » dai cua, hai cua, lai cua
ve nham » ve nha, ve cham
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
sach ky » sach ty, sach kem, sach hay
sac ky » cac ky, sai ky
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((((sach ky) OR (sach y))) or (sac ky)) tang mai hoi. hieu ve nham thuc dan dinh vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((((sach ky) OR (sach y))) OR (sac ky)) tang mai hoi. hieu ve nham thuc dan dinh vai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((((sach ky) OR (sach y))) or (sac ky)) tang mai hoi. hieu ve nham thuc dan dinh vai cua te".
• Adding a wildcard symbol may retrieve word variants: thu ((((sach ky) OR (sach y))) or (sac ky)) tang mai hoi. hieu ve nham thuc dan dinh vai cua te*.