Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
nam tuc » nam thuc, nam truc, nam tu
va tinh » may tinh
y nang » ly nang, v nang, may nang
ma hoi » mai hoi, xa hoi, ma hoa
tuc va » thuc va, truc va, tuc xa
ve cua » le cua, de cua, ve cum
te cua » tue cua, le cua, de cua

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 ((y nang) or (ky nang)) ma hoi. hieu van nam tuc va tinh ((ve cua) or (te cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((y nang) OR (ky nang)) ma hoi. hieu van nam tuc va tinh ((ve cua) OR (te cua)) tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ((y nang) or (ky nang)) ma hoi. hieu van nam tuc va tinh ((ve cua) or (te cua)) tre*.