Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
anh thai » anh tai, nhanh thai, tranh thai
cac xuc » cam xuc, cac nuoc, chat xuc
anh thi » anh tho, dinh thi, dang thi
xuc van » duc van, luc van, vuc van
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
o hai » co hai, so hai, o lai
o hoi » co hoi, o hoc, o hoa

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 ky nang ((o hoi) or (o hai)). hieu va cac xuc van ((anh thai) OR (anh thi)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ((o hoi) OR (o hai)). hieu va cac xuc van ((anh thai) OR (anh thi)) cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ((o hoi) or (o hai)). hieu va cac xuc van ((anh thai) OR (anh thi)) cau tren".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((o hoi) or (o hai)). hieu va cac xuc van ((anh thai) OR (anh thi)) cau tren*.