Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
vien cac » vien bach, vien dai, vien da
van hanh » van thanh, ban hanh, van anh
sach ty » sach y, sach tu, sach thu
ty lang » tay lang, ty xang, ty hang
lang xa » lang ha, dang xay, lang van
duc van » duc va, duc tan, duc manh
ve cac » va cac
vi cua » vai cua, di cua
cua cu » cua chu, cua cau, cua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ty lang xa hoi. hieu ((ve cac) or (vien cac)) duc van hanh vi cua cu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ty lang xa hoi. hieu ((ve cac) OR (vien cac)) duc van hanh vi cua cu.
• Adding a wildcard symbol may retrieve word variants: doc sach ty lang xa hoi. hieu ((ve cac) or (vien cac)) duc van hanh vi cua cu*.