Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hieu van » hieu va, thien van, lieu va
hanh tai » thanh tai, hang tai, han tai
cau phuc » cau truc, chau phu, huu phuc
cua tre » cua te, cua triet, dua tren
vu hanh » vu khanh, vu thanh, du hanh
van cau » van dau, van hau, van chat
cuu tre » cau tren, cau treo
y nang » ky nang, ly nang, may nang
ma hoi » mai hoi, xa hoi, ma hoa
v nang » va nang, vu nang, van nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ((y nang) OR (v nang)) ma hoi. hieu van cau phuc vu hanh tai ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ((y nang) OR (v nang)) ma hoi. hieu van cau phuc vu hanh tai ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ((y nang) OR (v nang)) ma hoi. hieu van cau phuc vu hanh tai ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ((y nang) OR (v nang)) ma hoi. hieu van cau phuc vu hanh tai ((cua tre) or (cuu tre))*.