Perhaps you should try some spelling variations:
loai tren » la tren, thai tren
cham xuc » cam xuc, chat xuc, cham soc
cau tren » cu tren, dau tren, ca tren
van hanh » van thanh, ban hanh, van anh
thu sach » tu sach, thuat sach, thuoc sach
hieu vu » hieu va, hieu ve, dieu vu
sach ky » sac ky, sach y, sach ty
xuc van » duc van, luc van, vuc van
dinh xa » dinh ba, dinh va, dinh xu
ky dinh » ky sinh, ky danh, ky kinh
hieu su » hieu sau, tieu su, hieu so

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

• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky dinh xa hoi. ((hieu vu) OR (hieu su)) cham xuc van hanh vi ((cau tren) OR (loai tren))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky dinh xa hoi. ((hieu vu) OR (hieu su)) cham xuc van hanh vi ((cau tren) or (loai tren))~".
• Adding a wildcard symbol may retrieve word variants: thu sach ky dinh xa hoi. ((hieu vu) OR (hieu su)) cham xuc van hanh vi ((cau tren) or (loai tren))*.