Perhaps you should try some spelling variations:
cao khoa » lao khoa, bao khoa, cac khoa
tu sach » thu sach, su sach, te sach
cam duc » cam xuc, cao duc, pham duc
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
cao hoa » cao hoat, cau hoa, cao hoc
ty nang » ky nang, ty xang, ty hang
cua tuc » cua duc, cua tu, cua thuoc
ve cam » ve cham, ve cac, va cam
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan va
cua te » cua tu

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 ty nang ((cao hoa) OR (cao khoa)). hieu ve cam duc va dan vi ((cua te) or (cua tuc))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((cao hoa) OR (cao khoa)). hieu ve cam duc va dan vi ((cua te) OR (cua tuc))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang ((cao hoa) OR (cao khoa)). hieu ve cam duc va dan vi ((cua te) or (cua tuc))*".