Perhaps you should try some spelling variations:
trinh tai » trinh toan, trinh tu, trinh han
duoc tren » nuoc tren, thuoc tren, dung tren
dang cau » hang cau, bang cau, dang mau
hinh tai » chinh tai, hinh thai, hinh bai
sach ty » sach y, sach tu, sach thu
duc tre » duc tien
su sach » so sach, vu sach
cac xuc » cam xuc, cac nuoc, chat xuc
hieu ve » hieu va, hieu van
cau hoa » cau hoi
ty dang » ty xang, ky dang, ty hang
xuc va » duc va, tuc va, luc va
ve cac » va cac, vien cac

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 ty dang cau hoa. hieu ve cac xuc va ((hinh tai) or (trinh tai)) ((duc tre) OR (duoc tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty dang cau hoa. hieu ve cac xuc va ((hinh tai) OR (trinh tai)) ((duc tre) OR (duoc tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty dang cau hoa. hieu ve cac xuc va ((hinh tai) or (trinh tai)) ((duc tre) OR (duoc tren))".
• Adding a wildcard symbol may retrieve word variants: su sach ty dang cau hoa. hieu ve cac xuc va ((hinh tai) or (trinh tai)) ((duc tre) OR (duoc tren))*.