Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
toc sach » hoc sach, doc sach, thuoc sach
cham tuc » nham thuc, tham thuc, cham soc
dan dat » dung dat, dong dat, dinh dat
cua tre » cua te, cuu tre, cua triet
ty nang » ky nang, ty xang, ty hang
sach ty » sach y, sach tu, sach thu
x hoi » xa hoi, o hoi, x ho

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

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