Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
dang xay » dang van, van xay
cham hoc » cham soc, chat hoc, cham hoi
dau tren » dau tien, dat tren, dau tieng
lang xa » lang ha, lang van
va cham » va chat, va tham
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
tu tren » tu truyen, tu tieng, tu trong

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach y ((lang xa) or (dang xay)) hoi. lieu va cham hoc va hanh va ((tu tren) or (dau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach y ((lang xa) OR (dang xay)) hoi. lieu va cham hoc va hanh va ((tu tren) OR (dau tren)).
• Adding a wildcard symbol may retrieve word variants: thuoc sach y ((lang xa) or (dang xay)) hoi. lieu va cham hoc va hanh va ((tu tren) or (dau tren))*.