Perhaps you should try some spelling variations:
hoat tinh » hoa tinh, ha tinh, hoi tinh
hieu van » hieu va, thien van, lieu va
vat tinh » sat tinh, vat sinh, vat chinh
dau tien » van tien
te sach » toc sach
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
lang ha » long ha
ca tren » cau tren, cu tren, la tren
ha hoi » hoa hoi, ha noi, xa hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky lang ha hoi. hieu van nam cua ((vat tinh) OR (hoat tinh)) va ((dau tien) or (ca tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky lang ha hoi. hieu van nam cua ((vat tinh) OR (hoat tinh)) va ((dau tien) OR (ca tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky lang ha hoi. hieu van nam cua ((vat tinh) OR (hoat tinh)) va ((dau tien) or (ca tren))".
• Adding a wildcard symbol may retrieve word variants: te sach ky lang ha hoi. hieu van nam cua ((vat tinh) OR (hoat tinh)) va ((dau tien) or (ca tren))*.