Manusmriti
यानि चैवम्प्रकाराणि कालाद् भूमिर्न भक्षयेत् । तानि सन्धिषु सीमायामप्रकाशानि कारयेत् ॥ २५१ ॥
And whatever other things of a similar kind the earth does not corrode even after a long time, those he should cause to be buried where one boundary joins (the other).
english translation
yAni caivamprakArANi kAlAd bhUmirna bhakSayet । tAni sandhiSu sImAyAmaprakAzAni kArayet ॥ 251 ॥
hk transliteration by Sanscript