Perhaps you should try some spelling variations:
hinh thai » sinh thai, tinh thai, dinh thi
vien cac » vien bach, vien dai, vien da
hanh tai » thanh tai, hang tai, han tai
sach ky » sac ky, sach y, sach ty
duc van » duc va, duc tan, duc manh
tu sach » thu sach, su sach, te sach
tang ho » tang cho, tung ho, tang ha
ky tang » ky nang, ky dang, kho tang
cuu tre » cua tre, cau tren, cau treo
ve cac » va cac
ho hai » hoc hai, pho hai, cho hai

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 ky tang ho hai. hieu ((ve cac) OR (vien cac)) duc van ((hanh tai) or (hinh thai)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky tang ho hai. hieu ((ve cac) OR (vien cac)) duc van ((hanh tai) OR (hinh thai)) cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky tang ho hai. hieu ((ve cac) OR (vien cac)) duc van ((hanh tai) or (hinh thai)) cuu tre*".