Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thu sach » tu sach, thuat sach, thu hoach
cau tren » dau tren, ca tren, cau treo
van hanh » van thanh, ban hanh, van anh
soc van » hoc van, oc van, sac van
va cham » va chat, va tham
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
cu tren » tu tren, dua tren

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