Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
cham tuc » nham thuc, pham thuc, cham soc
tinh vai » tinh va, tinh hai, tinh bai
su sach » vu sach
vai cua » dai cua, hai cua, lai cua
va tinh » may tinh
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
so sach » so sanh, bo sach, co sach
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (so sach)) ty nang xa hoi. hieu ve ((cham tuc) OR (tham thuc)) va tinh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ty nang xa hoi. hieu ve ((cham tuc) OR (tham thuc)) va tinh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sach)) ty nang xa hoi. hieu ve ((cham tuc) OR (tham thuc)) va tinh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sach)) ty nang xa hoi. hieu ve ((cham tuc) OR (tham thuc)) va tinh vai cua tre*.