▁kar st ▁ground water ▁bas in . ▁ ▁See ▁also ▁▁ ▁List ▁of ▁c aves ▁ ▁Spe le ology ▁ ▁References ▁ ▁Further ▁reading ▁S ides , ▁A . ▁G ., ▁and ▁S ides , ▁H ., ▁" J our ney ▁Tow ard ▁the ▁Center ▁of ▁the ▁Earth ," ▁The ▁Washington ▁Post ▁Magazine , ▁August ▁ 2 8 , ▁ 1 9 9 4 , ▁pp .   1 4 – 1 8 , ▁ 2 5 - 2 7 , ▁ ▁Robert ▁For rest ▁Burg ess . ▁The ▁C ave ▁D ivers . ▁Chapter ▁ 1 1 ▁Deep est ▁Qu est ▁Aqu a ▁Qu est ▁Publications , ▁Inc ., ▁ 1 9 9 9 , ▁ 3 5 1 ▁pages , ▁ISBN , ▁ 1 8 8 1 6 5 2 1 1 4 . ▁p ▁ 1 2 5 - 1 5 3 . ▁James ▁H . ▁Smith , ▁Jr ." H ydro ge ology ▁of ▁the ▁S istema ▁Hu aut la ▁kar st ▁gr oud water ▁bas in ." ▁Bul letin ▁of ▁Association ▁for ▁mex ican ▁cave ▁studies ▁( AM CS ) ▁n ° 9 , ▁ 2 0 0 2 , ▁ 1 5 4 ▁pages . ▁▁ ▁Stone , ▁W . ▁C ., ▁am ▁Ende , ▁B ., ▁and ▁Paul sen , ▁M ., ▁" B ey ond ▁the ▁Deep ", ▁ 2 0 0 2 , ▁Grand ▁Central ▁Publishing , ▁New ▁York , ▁NY , ▁ 3 6 8 ▁pp , ▁ ▁C . ▁William ▁Ste ele