Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
nang van » dang van, tang van, lang van
van hoi » van hoa, van hoc, van hoe
hieu va » lieu va, hieu qua
va pham » van pham, va phat, va phap
va hanh » van hanh, va thanh, va danh
hanh de » hanh ve, hanh kem
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
de cua » le cua, te cua, dieu cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) OR (doc sach)) y nang van hoi. hieu va pham duc va hanh de cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) y nang van hoi. hieu va pham duc va hanh de cua tre".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (doc sach)) y nang van hoi. hieu va pham duc va hanh de cua tre*.