Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cau tren » cu tren, dau tren, ca tren
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
hieu va » lieu va
va tinh » may tinh
tinh di » tinh doi, trinh di, tinh da
x hoi » xa hoi, o hoi, x ho

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 ty nang x hoi. ((hieu va) OR (hieu qua)) pham duc va tinh di ((cau tren) or (hoa viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty nang x hoi. ((hieu va) OR (hieu qua)) pham duc va tinh di ((cau tren) OR (hoa viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ty nang x hoi. ((hieu va) OR (hieu qua)) pham duc va tinh di ((cau tren) or (hoa viet))".
• Adding a wildcard symbol may retrieve word variants: thu sach ty nang x hoi. ((hieu va) OR (hieu qua)) pham duc va tinh di ((cau tren) or (hoa viet))*.