Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
cau tren » cu tren, ca tren, cau treo
quan cau » quang cao, toan cau, quan cua
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
truc va » thuc va, thuc vat, trung va
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
quan ha » quan he

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 dang xa hoi. hieu ((quan cau) or (quan ha)) truc va hanh va ((cau tren) OR (dau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky dang xa hoi. hieu ((quan cau) OR (quan ha)) truc va hanh va ((cau tren) OR (dau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky dang xa hoi. hieu ((quan cau) or (quan ha)) truc va hanh va ((cau tren) OR (dau tren))".
• Adding a wildcard symbol may retrieve word variants: su sach ky dang xa hoi. hieu ((quan cau) or (quan ha)) truc va hanh va ((cau tren) OR (dau tren))*.