Perhaps you should try some spelling variations:
hieu viet » sieu viet, hieu viec, lieu viet
viet tech » viet sach
tech nuoc » dich nuoc, sach nuoc
nang mai » nang ma, nang tai, lang mai
su sach » so sach, vu sach
sach ly » sach y, sach lo, sach ty
ly nang » ky nang, ly hang, ly vang
mai hoi » mai khoi, dai hoi, lai hoi
va xanh » va danh, va hanh, va anh
xanh di » danh di, vanh dai, xanh tai
cua tre » cuu tre, cua triet, dua tren
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: su sach ly nang mai hoi. hieu viet tech nuoc va xanh di ((cua tre) OR (cua te))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ly nang mai hoi. hieu viet tech nuoc va xanh di ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: su sach ly nang mai hoi. hieu viet tech nuoc va xanh di ((cua tre) OR (cua te))*.