Perhaps you should try some spelling variations:
thuat lanh » thuat lap, thuat san
tang mai » tang ma, tang tai, lang mai
tinh tai » trinh tai, tinh thai, tinh hai
hieu van » hieu va, thien van, lieu va
va tinh » may tinh
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
mai hoi » mai khoi, dai hoi, lai hoi
lanh y » anh y, hanh y, lanh lay
cam lo » cam ly, cam o
nam lo » nam bo, nam so, nam co
y tang » ky tang, 6 tang, 7 tang

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat lanh y tang mai hoi. hieu van ((cham h'roi) or (((cam lo) OR (nam lo)))) va tinh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat lanh y tang mai hoi. hieu van ((cham h'roi) OR (((cam lo) OR (nam lo)))) va tinh tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat lanh y tang mai hoi. hieu van ((cham h'roi) or (((cam lo) OR (nam lo)))) va tinh tai cua tre".
• Adding a wildcard symbol may retrieve word variants: thuat lanh y tang mai hoi. hieu van ((cham h'roi) or (((cam lo) OR (nam lo)))) va tinh tai cua tre*.