Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
nang mai » nang ma, nang tai, lang mai
mai khoa » tai khoa, may khoa, dai khoa
cam luc » cam xuc, cau luc
dan tai » van tai, dan thi, han tai
dan vai » dan va, dan vat, den vai
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
hieu ve » hieu van
luc va » duc va, tuc va, loc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky nang mai khoa. ((hieu ve) or (hieu va)) cam luc va ((dan vai) OR (dan tai)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang mai khoa. ((hieu ve) OR (hieu va)) cam luc va ((dan vai) OR (dan tai)) cau tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang mai khoa. ((hieu ve) or (hieu va)) cam luc va ((dan vai) OR (dan tai)) cau tren*".