Perhaps you should try some spelling variations:
sach tri » sach tai, sach tren, sach truc
tri nang » thi nang, tra nang, tri bang
ban hanh » ban hang
tu sach » thu sach, su sach, te sach
hoi cua » hoi chuc
doi cua » dai cua
cuc ban » cua ban, cac ban, cuu ban
cam cuc » cam xuc, cham cuu, pham cuc
hieu va » lieu va, hieu qua
cao hoi » cau hoi, co hoi, cao hoc
va cam » va cham, va cac, va cao
di cua » dai cua, de cua, do cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach tri nang cao hoi. hieu va cam cuc ban hanh ((di cua) or (((doi cua) OR (hoi cua)))) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tri nang cao hoi. hieu va cam cuc ban hanh ((di cua) OR (((doi cua) OR (hoi cua)))) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tri nang cao hoi. hieu va cam cuc ban hanh ((di cua) or (((doi cua) OR (hoi cua)))) tre".
• Adding a wildcard symbol may retrieve word variants: tu sach tri nang cao hoi. hieu va cam cuc ban hanh ((di cua) or (((doi cua) OR (hoi cua)))) tre*.