Perhaps you should try some spelling variations:
nhanh hai » nhanh thai, thanh hai, nhanh ha
va trien » va truyen, va thiet, va tuyen
cac truc » cau truc, cac tru, cac trung
hanh hai » thanh hai, hang hai, hanh tai
dang xay » dang van, van xay
truc van » truc va, thuc van, truc ban
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
dang xa » lang xa, dang ha, dang 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: tu sach ky ((dang xa) or (dang xay)) hoi. hieu ve cac truc van ((hanh hai) OR (nhanh hai)) va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((dang xa) OR (dang xay)) hoi. hieu ve cac truc van ((hanh hai) OR (nhanh hai)) va trien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((dang xa) or (dang xay)) hoi. hieu ve cac truc van ((hanh hai) OR (nhanh hai)) va trien".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((dang xa) or (dang xay)) hoi. hieu ve cac truc van ((hanh hai) OR (nhanh hai)) va trien*.