Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
dan thai » dang thai, dan thi, dan than
thai cua » than cua, tai cuc, tri cua
sach ky » sac ky, sach y, sach ty
co hoat » cao hoat, cac hoat, che hoat
van cac » van hac, van bac, dan cac
van cau » van dau, van hau, van chat
va dan » ca dan, va dao, va dau
cua te » cua tu
o hoa » do hoa, so hoa, o ha

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 ky nang ((o hoa) or (co hoat)). thien ((van cac) OR (van cau)) nuoc va dan thai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((o hoa) OR (co hoat)). thien ((van cac) OR (van cau)) nuoc va dan thai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang ((o hoa) or (co hoat)). thien ((van cac) OR (van cau)) nuoc va dan thai cua te".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ((o hoa) or (co hoat)). thien ((van cac) OR (van cau)) nuoc va dan thai cua te*.