Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thu sach » tu sach, thuat sach, thu hoach
dau tren » dau tien, dau tieng, dau trong
dat tren » dat trong, dua tren
va hanh » van hanh, va thanh, va danh
hanh ve » hanh vi, hanh va, hanh kem
cam loc » cam lo
nang o » nang co, nang ho, nang ro
va cam » va cham, va cac, va cao
loc va » hoc va, luc va
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (thuoc sach)) ky nang o hoi. lieu va cam loc va hanh ve ((dau tren) OR (dat tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuoc sach)) ky nang o hoi. lieu va cam loc va hanh ve ((dau tren) OR (dat tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (thuoc sach)) ky nang o hoi. lieu va cam loc va hanh ve ((dau tren) OR (dat tren))".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (thuoc sach)) ky nang o hoi. lieu va cam loc va hanh ve ((dau tren) OR (dat tren))*.