Perhaps you should try some spelling variations:
cham hoc » cham soc, chat hoc, cham hoi
ky trong » ly trong, ke trong, cay trong
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
ky dang » ky nang, ky danh
va dan » ca dan, va dao, va dau
tu sac » tu sach, tu cac, tu san
vi ca » vit ca, va ca, vi ha
li ca » ly ca

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ((ky dang) or (ky trong)) xa hoi. hieu ve cham hoc va dan ((vi ca) OR (li ca)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ((ky dang) OR (ky trong)) xa hoi. hieu ve cham hoc va dan ((vi ca) OR (li ca)) tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ((ky dang) or (ky trong)) xa hoi. hieu ve cham hoc va dan ((vi ca) OR (li ca)) tren".
• Adding a wildcard symbol may retrieve word variants: tu sac ((ky dang) or (ky trong)) xa hoi. hieu ve cham hoc va dan ((vi ca) OR (li ca)) tren*.